@article{3536, abstract = {Genetic engineering of the mouse brain allows investigators to address novel hypotheses in vivo. Because of the paucity of information on the network patterns of the mouse hippocampus, we investigated the electrical patterns in the behaving animal using multisite silicon probes and wire tetrodes. Theta (6-9 Hz) and gamma (40-100 Hz) oscillations were present during exploration and rapid eye movement sleep. Gamma power and theta power were comodulated and gamma power varied as a function of the theta cycle. Pyramidal cells and putative interneurons were phase-locked to theta oscillations. During immobility, consummatory behaviors and slow-wave sleep, sharp waves were present in cornu ammonis region CA1 of the hippocampus stratum radiatum associated with 140-200-Hz “ripples” in the pyramidal cell layer and population burst of CA1 neurons. In the hilus, large-amplitude “dentate spikes” occurred in association with increased discharge of hilar neurons. The amplitude of field patterns was larger in the mouse than in the rat, likely reflecting the higher neuron density in a smaller brain. We suggest that the main hippocampal network patterns are mediated by similar pathways and mechanisms in mouse and rat. }, author = {Buzsáki, György and Buhl, Derek and Harris, Kenneth and Csicsvari, Jozsef L and Czéh, Boldizsár and Morozov, Alexei}, issn = {1873-7544}, journal = {Neuroscience}, number = {1}, pages = {201 -- 211}, publisher = {Elsevier}, title = {{Hippocampal network patterns of activity in the mouse}}, doi = {10.1016/S0306-4522(02)00669-3}, volume = {116}, year = {2003}, } @inproceedings{3556, abstract = {We define the Morse-Smale complex of a Morse function over a 3-manifold as the overlay of the descending and as- cending manifolds of all critical points. In the generic case, its 3-dimensional cells are shaped like crystals and are sepa- rated by quadrangular faces. In this paper, we give a combi- natorial algorithm for constructing such complexes for piece- wise linear data.}, author = {Edelsbrunner, Herbert and Harer, John and Natarajan, Vijay and Pascucci, Valerio}, booktitle = {Proceedings of the nineteenth annual symposium in Computional geometry}, isbn = {9781581136630}, location = {San Diego, CA, United States}, pages = {361 -- 370}, publisher = {Association for Computing Machinery}, title = {{Morse-Smale complexes for piecewise linear 3-manifolds}}, doi = {10.1145/777792.777846}, year = {2003}, } @article{3543, abstract = {Both neocortical and hippocampal networks organize the firing patterns of their neurons by prominent oscillations during sleep, but the functional role of these rhythms is not well understood. Here, we show a robust correlation of neuronal discharges between the somatosensory cortex and hippocampus on both slow and fine time scales in the mouse and rat. Neuronal bursts in deep cortical layers, associated with sleep spindles and delta waves/slow rhythm, effectively triggered hippocampal discharges related to fast (ripple) oscillations. We hypothesize that oscillation-mediated temporal links coordinate specific information transfer between neocortical and hippocampal cell assemblies. Such a neocortical-hippocampal interplay may be important for memory consolidation.}, author = {Sirota, Anton and Csicsvari, Jozsef L and Buhl, Derek and Buzsáki, György}, issn = {1091-6490}, journal = {PNAS}, number = {4}, pages = {2065 -- 2069}, publisher = {National Academy of Sciences}, title = {{Communication between neocortex and hippocampus during sleep in rodents}}, doi = {10.1073/pnas.0437938100}, volume = {100}, year = {2003}, } @article{3528, abstract = {Gamma frequency oscillations (30-100 Hz) have been suggested to underlie various cognitive and motor functions. Here, we examine the generation of gamma oscillation currents in the hippocampus, using two-dimensional, 96-site silicon probes. Two gamma generators were identified, one in the dentate gyrus and another in the CA3-CA1 regions. The coupling strength between the two oscillators varied during both theta and nontheta states. Both pyramidal cells and interneurons were phase-locked to gamma waves. Anatomical connectivity, rather than physical distance, determined the coupling strength of the oscillating neurons. CA3 pyramidal neurons discharged CA3 and CA1 interneurons at latencies indicative of monosynaptic connections. Intrahippocampal gamma oscillation emerges in the CA3 recurrent system, which entrains the CA1 region via its interneurons.}, author = {Csicsvari, Jozsef L and Jamieson, Brian and Wise, Kensall and Buzsáki, György}, issn = {1097-4199}, journal = {Neuron}, number = {2}, pages = {311 -- 322}, publisher = {Elsevier}, title = {{Mechanisms of gamma oscillations in the hippocampus of the behaving rat}}, doi = {10.1016/S0896-6273(02)01169-8}, volume = {37}, year = {2003}, } @inbook{3458, author = {Jonas, Peter M and Unsicker, Klaus}, booktitle = {Lehrbuch Vorklinik}, editor = {Schmidt, R.}, isbn = {9783769104431}, pages = {3 -- 26}, publisher = {Deutscher Ärzteverlag}, title = {{Molekulare und zelluläre Grundlagen des Nervensystems}}, volume = {B}, year = {2003}, } @inproceedings{3425, abstract = {Recent observations of the polarization of the light emitted by supernova explo-sions indicate that there are large deviations from spherical symmetry in the very heart of these explosions. Asymmetries may well play a key role in the explosion mechanism. So far there is no convincing theoretical explanation for these observations. In this work the impact of angular momentum on the core collapse which is possibly the origin of large asymmetries is studied. We introduce a new approach to the supernova problem: a three dimensional test particle based simulation. The infall phase of the collapse of a typical iron core is investigated using numerical calculations. Our main focus is the impact of angular momentum. Significant deviations from spherical symmetry are found for rapidly rotating supernova cores.}, author = {Bollenbach, Mark Tobias and Strother, T. and Bauer, Wolfgang}, isbn = {9781402024467}, pages = {277 -- 288}, publisher = {Springer Nature}, title = {{3D supernova collapse calculations}}, doi = {10.1007/978-1-4020-2705-5_21}, volume = {166}, year = {2003}, } @inproceedings{3210, abstract = {Luby and Rackoff showed how to construct a (super-)pseudo-random permutation {0,1}2n→ {0,1}2n from some number r of pseudo-random functions {0,1}n → {0,1}n. Their construction, motivated by DES, consists of a cascade of r Feistel permutations. A Feistel permutation 1for a pseudo-random function f is defined as (L, R) → (R,L ⊕ f (R)), where L and R are the left and right part of the input and ⊕ denotes bitwise XOR or, in this paper, any other group operation on {0,1}n. The only non-trivial step of the security proof consists of proving that the cascade of r Feistel permutations with independent uniform random functions {0,1}n → {0,1}n, denoted Ψ2nr is indistinguishable from a uniform random permutation {0,1}2n → {0,1}2n by any computationally unbounded adaptive distinguisher making at most O(2cn) combined chosen plaintext/ciphertext queries for any c < α, where a is a security parameter. Luby and Rackoff proved α = 1/2 for r = 4. A natural problem, proposed by Pieprzyk is to improve on α for larger r. The best known result, α = 3/4 for r = 6, is due to Patarin. In this paper we prove a = 1 -O(1/r), i.e., the trivial upper bound α = 1 can be approached. The proof uses some new techniques that can be of independent interest. }, author = {Maurer, Ueli and Pietrzak, Krzysztof Z}, isbn = {9783540140399}, location = {Warschau, Polen}, pages = {544 -- 561}, publisher = {Springer Nature}, title = {{The security of many round Luby Rackoff pseudo random permutations}}, doi = {10.1007/3-540-39200-9_34}, volume = {2656}, year = {2003}, } @article{3209, abstract = {We show that the fixed alphabet shortest common supersequence (SCS) and the fixed alphabet longest common subsequence (LCS) problems parameterized in the number of strings are W[1]-hard. Unless W[1]=FPT, this rules out the existence of algorithms with time complexity of O(f(k)nα) for those problems. Here n is the size of the problem instance, α is constant, k is the number of strings and f is any function of k. The fixed alphabet version of the LCS problem is of particular interest considering the importance of sequence comparison (e.g. multiple sequence alignment) in the fixed length alphabet world of DNA and protein sequences.}, author = {Pietrzak, Krzysztof Z}, journal = {Journal of Computer and System Sciences}, number = {4}, pages = {757 -- 771}, publisher = {Elsevier}, title = {{On the parameterized complexity of the fixed alphabet shortest common supersequence and longest common subsequence problems}}, doi = {10.1016/S0022-0000(03)00078-3}, volume = {67}, year = {2003}, } @inproceedings{3171, abstract = {Reconstructing a 3-D scene from more than one camera is a classical problem in computer vision. One of the major sources of difficulty is the fact that not all scene elements are visible from all cameras. In the last few years, two promising approaches have been developed 11,12 that formulate the scene reconstruction problem in terms of energy minimization, and minimize the energy using graph cuts. These energy minimization approaches treat the input images symmetrically, handle visibility constraints correctly, and allow spatial smoothness to be enforced. However, these algorithm propose different problem formulations, and handle a limited class of smoothness terms. One algorithm 11 uses a problem formulation that is restricted to two-camera stereo, and imposes smoothness between a pair of cameras. The other algorithm 12 can handle an arbitrary number of cameras, but imposes smoothness only with respect to a single camera. In this paper we give a more general energy minimization formulation for the problem, which allows a larger class of spatial smoothness constraints. We show that our formulation includes both of the previous approaches as special cases, as well as permitting new energy functions. Experimental results on real data with ground truth are also included. }, author = {Kolmogorov, Vladimir and Zabih, Ramin and Gortler, Steven}, booktitle = {4th International Workshop}, isbn = {9783540404989}, location = {Lisbon, Portugal}, pages = {501 -- 516}, publisher = {Springer Nature}, title = {{Generalized multi camera scene reconstruction using graph cuts}}, doi = {10.1007/978-3-540-45063-4_32}, volume = {2683}, year = {2003}, } @article{3150, abstract = {Tripartite G-protein-coupled receptors (GPCRs) represent one of the largest groups of signal transducers, transmitting signals from hormones, neuropeptides, odorants, food and light. Ligand-bound receptors catalyse GDP/GTP exchange on the G-protein α-subunit (Gα), leading to α-GTP separation from the βγ subunits and pathway activation. Activating mutations in the receptors or G proteins underlie many human diseases, including some cancers, dwarfism and premature puberty. Regulators of G-protein signalling (RGS proteins) are known to modulate the level and duration of ligand-induced signalling by accelerating the intrinsic GTPase activity of the Gα subunit, and thus reformation of the inactive GDP-bound Gα. Here we find that even in the absence of receptor, mutation of the RGS family member Sst2 (refs 6-9) permits spontaneous activation of the G-protein-coupled mating pathway in Saccharomyces cerevisiae at levels normally seen only in the presence of ligand. Our work demonstrates the occurence of spontaneous tripartite G-protein signalling in vivo and identifies a requirement for RGS proteins in preventing such receptor-independent activation.}, author = {Siekhaus, Daria E and Drubin, David}, issn = {1476-4679}, journal = {Nature Cell Biology}, number = {3}, pages = {231 -- 235}, publisher = {Springer Nature}, title = {{Spontaneous receptor-independent heterotrimeric G-protein signalling in an RGS mutant}}, doi = {10.1038/ncb941}, volume = {5}, year = {2003}, } @article{3151, abstract = {Biosynthesis of most peptide hormones and neuropeptides requires proteolytic excision of the active peptide from inactive proprotein precursors, an activity carried out by subtilisin-like proprotein convertases (SPCs) in constitutive or regulated secretory pathways. The Drosophila amontillado (amon) gene encodes a homolog of the mammalian PC2 protein, an SPC that functions in the regulated secretory pathway in neuroendocrine tissues. We have identified amon mutants by isolating ethylmethanesulfonate (EMS)-induced lethal and visible mutations that define two complementation groups in the amon interval at 97D1 of the third chromosome. DNA sequencing identified the amon complementation group and the DNA sequence change for each of the nine amon alleles isolated. amon mutants display partial embryonic lethality, are defective in larval growth, and arrest during the first to second instar larval molt. Mutant larvae can be rescued by heat-shock-induced expression of the amon protein. Rescued larvae arrest at the subsequent larval molt, suggesting that amon is also required for the second to third instar larval molt. Our data indicate that the amon proprotein convertase is required during embryogenesis and larval development in Drosophila and support the hypothesis that AMON acts to proteolytically process peptide hormones that regulate hatching, larval growth, and larval ecdysis.}, author = {Rayburn, Lowell and Gooding, Holly and Choksi, Semil and Maloney, Dhea and Kidd, Ambrose and Siekhaus, Daria E and Bender, Michael}, issn = {1943-2631}, journal = {Genetics}, number = {1}, pages = {227 -- 237}, publisher = {Oxford Academic}, title = {{Amontillado, the Drosophila homolog of the prohormone processing protease PC2, is required during embryogenesis and early larval development}}, doi = {10.1093/genetics/163.1.227}, volume = {163}, year = {2003}, } @article{2996, abstract = {Plants, compared to animals, exhibit an amazing adaptability and plasticity in their development. This is largely dependent on the ability of plants to form new organs, such as lateral roots, leaves, and flowers during postembryonic development. Organ primordia develop from founder cell populations into organs by coordinated cell division and differentiation. Here, we show that organ formation in Arabidopsis involves dynamic gradients of the signaling molecule auxin with maxima at the primordia tips. These gradients are mediated by cellular efflux requiring asymmetrically localized PIN proteins, which represent a functionally redundant network for auxin distribution in both aerial and underground organs. PIN1 polar localization undergoes a dynamic rearrangement, which correlates with establishment of auxin gradients and primordium development. Our results suggest that PIN-dependent, local auxin gradients represent a common module for formation of all plant organs, regardless of their mature morphology or developmental origin. }, author = {Benková, Eva and Michniewicz, Marta and Sauer, Michael and Teichmann, Thomas and Seifertová, Daniela and Jürgens, Gerd and Friml, Jirí}, issn = {1097-4172}, journal = {Cell}, number = {5}, pages = {591 -- 602}, publisher = {Cell Press}, title = {{Local, efflux-dependent auxin gradients as a common module for plant organ formation}}, doi = {10.1016/S0092-8674(03)00924-3}, volume = {115}, year = {2003}, } @article{2992, abstract = {Plants have many polarized cell types, but relatively little is known about the mechanisms that establish polarity. The orc mutant was identified originally by defects in root patterning, and positional cloning revealed that the affected gene encodes STEROL METHYLTRANSFERASE1, which is required for the appropriate synthesis and composition of major membrane sterols. smt1orc mutants displayed several conspicuous cell polarity defects. Columella root cap cells revealed perturbed polar positioning of different organelles, and in the smt1orc root epidermis, polar initiation of root hairs was more randomized. Polar auxin transport and expression of the auxin reporter DR5-β-glucuronidase were aberrant in smt1orc. Patterning defects in smt1orc resembled those observed in mutants of the PIN gene family of putative auxin efflux transporters. Consistently, the membrane localization of the PIN1 and PIN3 proteins was disturbed in smt1orc, whereas polar positioning of the influx carrier AUX1 appeared normal. Our results suggest that balanced sterol composition is a major requirement for cell polarity and auxin efflux in Arabidopsis.}, author = {Willemsen, Viola and Friml, Jirí and Grebe, Markus and Van Den Toorn, Albert and Palme, Klaus and Scheres, Ben}, issn = {1532-298X}, journal = {Plant Cell}, number = {3}, pages = {612 -- 625}, publisher = {American Society of Plant Biologists}, title = {{Cell polarity and PIN protein positioning in Arabidopsis require STEROL METHYLTRANSFERASE1 function}}, doi = {10.1105/tpc.008433}, volume = {15}, year = {2003}, } @article{2994, abstract = {The regular arrangement of leaves around a plant's stem, called phyllotaxis, has for centuries attracted the attention of philosophers, mathematicians and natural scientists; however, to date, studies of phyllotaxis have been largely theoretical. Leaves and flowers are formed from the shoot apical meristem, triggered by the plant hormone auxin. Auxin is transported through plant tissues by specific cellular influx and efflux carrier proteins. Here we show that proteins involved in auxin transport regulate phyllotaxis. Our data indicate that auxin is transported upwards into the meristem through the epidermis and the outermost meristem cell layer. Existing leaf primordia act as sinks, redistributing auxin and creating its heterogeneous distribution in the meristem. Auxin accumulation occurs only at certain minimal distances from existing primordia, defining the position of future primordia. This model for phyllotaxis accounts for its reiterative nature, as well as its regularity and stability.}, author = {Reinhardt, Didier and Pesce, Eva and Stieger, Pia and Mandel, Therese and Baltensperger, Kurt and Bennett, Malcolm and Traas, Jan and Friml, Jirí and Kuhlemeier, Cris}, issn = {1476-4687}, journal = {Nature}, pages = {255 -- 260}, publisher = {Springer Nature}, title = {{Regulation of phyllotaxis by polar auxin transport}}, doi = {10.1038/nature02081}, volume = {426}, year = {2003}, } @article{2993, abstract = {Plant biology is currently experiencing a growing demand for easy and reliable mRNA and protein localisation techniques. Here, we present novel whole mount in situ hybridisation and immunolocalisation protocols, suitable to localise mRNAs and proteins in Arabidopsis seedlings. We demonstrate that these methods can be used in different organs of Arabidopsis seedlings as well as in other plant species. In order to achieve better reproducibility and higher throughput, we modified these protocols for automation to be performed by a liquid handling robot. In addition, we show that other procedures such as reporter enzyme assays and tissue clearing can be similarly automated. We present examples of application of our protocols including mRNA localisation and proteins and epitope tag (co)localisations which demonstrate that these methods provide reliable and versatile tools for expression, localisation and anatomical studies in plants.}, author = {Friml, Jirí and Benková, Eva and Mayer, Ulrike and Palme, Klaus and Muster, Gerhard}, issn = {1365-313X}, journal = {Plant Journal}, number = {1}, pages = {115 -- 124}, publisher = {Wiley}, title = {{Automated whole mount localisation techniques for plant seedlings}}, doi = {10.1046/j.1365-313X.2003.01705.x}, volume = {34}, year = {2003}, } @article{2995, abstract = {Axis formation occurs in plants, as in animals, during early embryogenesis. However, the underlying mechanism is not known. Here we show that the first manifestation of the apical-basal axis in plants, the asymmetric division of the zygote, produces a basal cell that transports and an apical cell that responds to the signalling molecule auxin. This apical-basal auxin activity gradient triggers the specification of apical embryo structures and is actively maintained by a novel component of auxin efflux, PIN7, which is located apically in the basal cell. Later, the developmentally regulated reversal of PIN7 and onset of PIN1 polar localization reorganize the auxin gradient for specification of the basal root pole. An analysis of pin quadruple mutants identifies PIN-dependent transport as an essential part of the mechanism for embryo axis formation. Our results indicate how the establishment of cell polarity, polar auxin efflux and local auxin response result in apical-basal axis formation of the embryo, and thus determine the axiality of the adult plant. }, author = {Friml, Jirí and Vieten, Anne and Sauer, Michael and Weijers, Dolf and Schwarz, Heinz and Hamann, Thorsten and Offringa, Remko and Jürgens, Gerd}, issn = {1476-4687}, journal = {Nature}, pages = {147 -- 153}, publisher = {Springer Nature}, title = {{Efflux dependent auxin gradients establish the apical basal axis of Arabidopsis}}, doi = {10.1038/nature02085}, volume = {426}, year = {2003}, } @misc{3139, author = {Chen, Hsiao and Hippenmeyer, Simon and Arber, Silvia and Frank, Eric}, booktitle = {Current Opinion in Neurobiology}, issn = {1873-6882}, number = {1}, pages = {96 -- 102}, publisher = {Elsevier}, title = {{Development of the monosynaptic stretch reflex circuit}}, doi = {10.1016/S0959-4388(03)00006-0}, volume = {13}, year = {2003}, } @article{2633, abstract = {The modulation of calcium channels by metabotropic glutamate receptors (mGluRs) is a key event in the fine-tuning of neurotransmitter release. Here we report that, in cerebrocortical nerve terminals of adult rats, the inhibition of glutamate release is mediated by mGluR7. In this preparation, the major component of glutamate release is supported by P/Q-type Ca2+ channels (72.7%). However, mGluR7 selectively reduced the release component that is associated with N-type Ca2+ channels (29.9%). Inhibition of P/Q channels by mGluR7 is not masked by the higher efficiency of these channels in driving glutamate release when compared with N-type channels. Thus, activation of mGluR7 failed to reduce the release associated with P/Q channels when the extracellular calcium concentration, ([Ca2+]o), was reduced from 1.3 to 0.5 mM. Through Ca2+ imaging, we show that Ca2+ channels are distributed in a heterogeneous manner in individual nerve terminals. Indeed, in this preparation, nerve terminals were observed that contain N-type (31.1%; conotoxin GVIA-sensitive) or P/Q-type (64.3%; agatoxin IVA-sensitive) channels or that were insensitive to these two toxins (4.6%). Interestingly, the great majority of the responses to L-AP4 (95.4%) were observed in nerve terminals containing N-type channels. This specific co-localization of mGluR7 and N-type Ca2+-channels could explain the failure of the receptor to inhibit the P/Q channel-associated release component and also reveal the existence of specific targeting mechanisms to localize the two proteins in the same nerve terminal subset.}, author = {Millán, Carmelo and Castro, Enrique and Torres, Magdalena and Shigemoto, Ryuichi and Sánchez Prieto, José}, issn = {1083-351X}, journal = {Journal of Biological Chemistry}, number = {26}, pages = {23955 -- 23962}, publisher = {Elsevier}, title = {{Co-expression of metabotropic glutamate receptor 7 and N-type Ca2+ channels in single cerebrocortical nerve terminals of adult rats}}, doi = {10.1074/jbc.M211471200}, volume = {278}, year = {2003}, } @article{2635, abstract = {Metabotropic GABAB receptors mediate slow inhibitory effects presynaptically and postsynaptically. Using preembedding immunohistochemical methods combined with quantitative analysis of GABAB receptor subunit immunoreactivity, this study provides a detailed description of the cellular and subcellular localization of GABAB1a/b and GABA B2 in the rat hippocampus. At the light microscopic level, an overlapping distribution of GABAB1a/b and GABAB2 was revealed in the dendritic layers of the hippocampus. In addition, expression of the GABAB1a/b subunit was found in somata of CA1 pyramidal cells and of a subset of GABAergic interneurons. At the electron microscopic level, immunoreactivity for both subunits was observed on presynaptic and, more abundantly, on postsynaptic elements. Presynaptically, subunits were mainly detected in the extrasynaptic membrane and occasionally over the presynaptic membrane specialization of putative glutamatergic and, to a lesser extent, GABAergic axon terminals. Postsynaptically, the majority of GABAB receptor subunits were localized to the extrasynaptic plasma membrane of spines and dendritic shafts of principal cells and shafts of interneuron dendrites. Quantitative analysis revealed enrichment of GABAB1a/b around putative glutamatergic synapses on spines and an even distribution on dendritic shafts of pyramidal cells contacted by GABAergic boutons. The association of GABAB receptors with glutamatergic synapses at both presynaptic and postsynaptic sides indicates their intimate involvement in the modulation of glutamatergic neurotransmission. The dominant extrasynaptic localization of GABAB receptor subunits suggests that their activation is dependent on spillover of GABA requiring simultaneous activity of populations of GABAergic cells as it occurs during population oscillations or epileptic seizures.}, author = {Kulik, Ákos and Vida, Imre and Luján, Rafael and Haas, Carola and López Bendito, Guillermina and Shigemoto, Ryuichi and Frotscher, Michael}, issn = {1529-2401}, journal = {Journal of Neuroscience}, number = {35}, pages = {11026 -- 11035}, publisher = {Society for Neuroscience}, title = {{Subcellular Localization of Metabotropic GABAB Receptor Subunits GABAB1a/b and GABAB2 in the Rat Hippocampus}}, doi = {10.1523/JNEUROSCI.23-35-11026.2003}, volume = {23}, year = {2003}, } @article{2632, abstract = {In many brain regions, hyperpolarization-activated cationic currents (Ih) are involved in the generation of rhythmic activities, but the role of Ih in olfactory oscillations remains unclear. Knowledge of the cellular and subcellular distributions of hyperpolarization-activated and cyclic nucleotide-gated channel (HCN) subunits is necessary for understanding the role of Ih in olfactory network activities. Using light microscopic immunocytochemistry, we demonstrate strong HCN1 labelling of the glomerular layer and moderate staining of granule cell, internal and external plexiform layers of the rat main olfactory bulb. In the glomerular layer, among many unlabelled neurons, two distinct subpopulations of juxtaglomerular cells are labelled. Approximately 10% of the juxtaglomerular cells strongly express HCN1. These small diameter cells are immunoreactive for GABA and comprise a subpopulation of periglomerular cells. An additional subset of juxtaglomerular cells (≈ 1%) expresses low levels of HCN1. They are large in diameter, GABA immunonegative but immunopositive for vesicular glutamate transporter 2, characterizing them as external tufted cells. Quantitative immunogold localization revealed that the somatic plasma membranes of periglomerular cells contain approximately four times more HCN1 labelling than those of external tufted cells. Unlike in cortical pyramidal cells, immunogold density for HCN1 does not significantly differ in somatic and dendritic plasma membranes of external tufted cells, indicating that post-synaptic potentials arriving at proximal and distal dendrites are modulated by the same density of I h. Our results demonstrate a cell type-dependent expression of HCN1 in the olfactory bulb and predict a differential contribution of distinct juxtaglomerular cell types to network oscillations.}, author = {Holderith, Noémi and Shigemoto, Ryuichi and Nusser, Zoltán}, issn = {1460-9568}, journal = {European Journal of Neuroscience}, number = {2}, pages = {344 -- 354}, publisher = {Wiley-Blackwell}, title = {{Cell type-dependent expression of HCN1 in the main olfactory bulb}}, doi = {10.1046/j.1460-9568.2003.02756.x}, volume = {18}, year = {2003}, }