@article{MTMT:1031123,
	title = {Spike train dynamics predicts theta-related phase precession in hippocampal pyramidal cells.},
	url = {https://m2.mtmt.hu/api/publication/1031123},
	author = {Harris, K D and Henze, D A and Hirase, H and Leinekugel, X and Dragoi, G and Czurkó, András and Buzsáki, György},
	doi = {10.1038/nature00808},
	journal-iso = {NATURE},
	journal = {NATURE},
	volume = {417},
	unique-id = {1031123},
	issn = {0028-0836},
	abstract = {According to the temporal coding hypothesis, neurons encode information by the exact timing of spikes. An example of temporal coding is the hippocampal phase precession phenomenon, in which the timing of pyramidal cell spikes relative to the theta rhythm shows a unidirectional forward precession during spatial behaviour. Here we show that phase precession occurs in both spatial and non-spatial behaviours. We found that spike phase correlated with instantaneous discharge rate, and processed unidirectionally at high rates, regardless of behaviour. The spatial phase precession phenomenon is therefore a manifestation of a more fundamental principle governing the timing of pyramidal cell discharge. We suggest that intrinsic properties of pyramidal cells have a key role in determining spike times, and that the interplay between the magnitude of dendritic excitation and rhythmic inhibition of the somatic region is responsible for the phase assignment of spikes.},
	year = {2002},
	eissn = {1476-4687},
	pages = {738-741},
	orcid-numbers = {Czurkó, András/0000-0002-1985-7296}
}

@article{MTMT:1228630,
	title = {Intrahippocampal gamma and theta rhythm generation in a network model of inhibitory interneurons},
	url = {https://m2.mtmt.hu/api/publication/1228630},
	author = {Kiss, Tamás and Orbán, Gergő and Lengyel, M and Érdi, Péter},
	doi = {10.1016/S0925-2312(01)00358-7},
	journal-iso = {NEUROCOMPUTING},
	journal = {NEUROCOMPUTING},
	volume = {38-40},
	unique-id = {1228630},
	issn = {0925-2312},
	year = {2001},
	eissn = {1872-8286},
	pages = {713-719}
}

@article{MTMT:1228244,
	title = {Hippocampal rhythm generation: Gamma-related theta-frequency resonance in CA3 interneurons},
	url = {https://m2.mtmt.hu/api/publication/1228244},
	author = {Orbán, Gergő and Kiss, Tamás and Lengyel, M and Érdi, Péter},
	doi = {10.1007/s004220000199},
	journal-iso = {BIOL CYBERN},
	journal = {BIOLOGICAL CYBERNETICS},
	volume = {84},
	unique-id = {1228244},
	issn = {0340-1200},
	abstract = {During different behavioral states different population activities are
		present in the hippocampal formation. These activities are not
		independent: sharp waves often occur together with high-frequency
		ripples, and gamma-frequency activity is usually superimposed on theta
		oscillations. There is both experimental and theoretical evidence
		supporting the notion that gamma oscillation is generated
		intrahippocampally, but there is no generally accepted view about the
		origin of theta waves. Precise timing of population bursts of pyramidal
		cells may be due to a synchronized external drive. Membrane potential
		oscillations recorded in the septum are unlikely to fulfill this
		purpose because they are not coherent enough. We investigated the
		prospects of an intrahippocampal mechanism supplying pyramidal cells
		with theta frequency periodic inhibition, by studying a model of a
		network of hippocampal inhibitory interneurons. As shown previously,
		interneurons are capable of generating synchronized gamma-frequency
		action potential oscillations. Exciting the neurons by periodic current
		injection, the system could either be entrained in an oscillation with
		the frequency of the inducing current or exhibit in-phase periodic
		changes at the frequency of single cell (and network) activity.
		Simulations that used spatially inhomogeneous stimulus currents showed
		antiphase frequency changes across cells, which resulted in a periodic
		decrease in the synchrony of the network. As this periodic change in
		synchrony occurred in the theta frequency range, our network should be
		able to exhibit the theta-frequency weakening of inhibition of
		pyramidal cells, thus offering a possible mechanism for
		intrahippocampal theta generation.},
	year = {2001},
	eissn = {1432-0770},
	pages = {123-132}
}

@article{MTMT:1031133,
	title = {Oscillatory coupling of hippocampal pyramidal cells and interneurons in the behaving Rat.},
	url = {https://m2.mtmt.hu/api/publication/1031133},
	author = {Csicsvari, J and Hirase, H and Czurkó, András and Mamiya, A and Buzsáki, György},
	doi = {10.1523/jneurosci.19-01-00274.1999},
	journal-iso = {J NEUROSCI},
	journal = {JOURNAL OF NEUROSCIENCE},
	volume = {19},
	unique-id = {1031133},
	issn = {0270-6474},
	abstract = {We examined whether excitation and inhibition are balanced in hippocampal cortical networks. Extracellular field and single-unit activity were recorded by multiple tetrodes and multisite silicon probes to reveal the timing of the activity of hippocampal CA1 pyramidal cells and classes of interneurons during theta waves and sharp wave burst (SPW)-associated field ripples. The somatic and dendritic inhibition of pyramidal cells was deduced from the activity of interneurons in the pyramidal layer [int(p)] and in the alveus and st. oriens [int(a/o)], respectively. Int(p) and int(a/o) discharged an average of 60 and 20 degrees before the population discharge of pyramidal cells during the theta cycle, respectively. SPW ripples were associated with a 2.5-fold net increase of excitation. The discharge frequency of int(a/o) increased, decreased ("anti-SPW" cells), or did not change ("SPW-independent" cells) during SPW, suggesting that not all interneurons are innervated by pyramidal cells. Int(p) either fired together with (unimodal cells) or both before and after (bimodal cells) the pyramidal cell burst. During fast-ripple oscillation, the activity of interneurons in both the int(p) and int(a/o) groups lagged the maximum discharge probability of pyramidal neurons by 1-2 msec. Network state changes, as reflected by field activity, covaried with changes in the spike train dynamics of single cells and their interactions. Summed activity of parallel-recorded interneurons, but not of pyramidal cells, reliably predicted theta cycles, whereas the reverse was true for the ripple cycles of SPWs. We suggest that network-driven excitability changes provide temporal windows of opportunity for single pyramidal cells to suppress, enable, or facilitate selective synaptic inputs.},
	year = {1999},
	eissn = {1529-2401},
	pages = {274-287},
	orcid-numbers = {Czurkó, András/0000-0002-1985-7296}
}

@article{MTMT:108648,
	title = {Postsynaptic targets of somatostatin-immunoreactive interneurons in the rat hippocampus},
	url = {https://m2.mtmt.hu/api/publication/108648},
	author = {Katona, István and Acsády, László and Freund, Tamás},
	doi = {10.1016/S0306-4522(98)00302-9},
	journal-iso = {NEUROSCIENCE},
	journal = {NEUROSCIENCE},
	volume = {88},
	unique-id = {108648},
	issn = {0306-4522},
	year = {1999},
	eissn = {1873-7544},
	pages = {37-55}
}

@article{MTMT:108577,
	title = {Theta oscillations in somata and dendrites of hippocampal pyramidal cells in vivo: activity-dependent phase-precession of action potentials},
	url = {https://m2.mtmt.hu/api/publication/108577},
	author = {Kamondi, Anita and Acsády, László and Wang, XJ and Buzsáki, György},
	doi = {10.1002/(SICI)1098-1063(1998)8:3<244::AID-HIPO7>3.0.CO;2-J},
	journal-iso = {HIPPOCAMPUS},
	journal = {HIPPOCAMPUS},
	volume = {8},
	unique-id = {108577},
	issn = {1050-9631},
	year = {1998},
	eissn = {1098-1063},
	pages = {244-261},
	orcid-numbers = {Kamondi, Anita/0000-0001-9860-730X}
}

@article{MTMT:107892,
	title = {Disinhibition of rat hippocampal pyramidal cells by GABAergic afferents from the septum},
	url = {https://m2.mtmt.hu/api/publication/107892},
	author = {Tóth, Katalin and Freund, Tamás and Miles, R},
	doi = {10.1113/jphysiol.1997.sp022033},
	journal-iso = {J PHYSIOL-LONDON},
	journal = {JOURNAL OF PHYSIOLOGY-LONDON},
	volume = {500},
	unique-id = {107892},
	issn = {0022-3751},
	year = {1997},
	eissn = {1469-7793},
	pages = {463-474}
}

@article{MTMT:107931,
	title = {Interneurons of the hippocampus},
	url = {https://m2.mtmt.hu/api/publication/107931},
	author = {Freund, Tamás and Buzsáki, György},
	doi = {10.1002/(SICI)1098-1063(1996)6:4<347::AID-HIPO1>3.0.CO;2-I},
	journal-iso = {HIPPOCAMPUS},
	journal = {HIPPOCAMPUS},
	volume = {6},
	unique-id = {107931},
	issn = {1050-9631},
	year = {1996},
	eissn = {1098-1063},
	pages = {347-470}
}

@article{MTMT:1263778,
	title = {The hippocampus as a cognitive graph},
	url = {https://m2.mtmt.hu/api/publication/1263778},
	author = {R U, Muller and M, Stead and Pach, János},
	doi = {10.1085/jgp.107.6.663},
	journal-iso = {J GEN PHYSIOL},
	journal = {JOURNAL OF GENERAL PHYSIOLOGY},
	volume = {107},
	unique-id = {1263778},
	issn = {0022-1295},
	abstract = {A theory of cognitive mapping is developed that depends only on accepted properties of hippocampal function, namely, long-term potentiation, the place cell phenomenon, and the associative or recurrent connections made among CA3 pyramidal cells. It is proposed that the distance between the firing fields of connected pairs of CA3 place cells is encoded as synaptic resistance (reciprocal synaptic strength). The encoding occurs because pairs of cells with coincident or overlapping fields will tend to fire together in time, thereby causing a decrease in synaptic resistance via long-term potentiation; in contrast, cells with widely separated fields will tend never to fire together, causing no change or perhaps (via long-term depression) an increase in synaptic resistance. A network whose connection pattern mimics that of CA3 and whose connection weights are proportional to synaptic resistance can be formally treated as a weighted, directed graph. In such a graph, a ''node'' is assigned to each CA3 cell and two nodes are connected by a ''directed edge'' if and only if the two corresponding cells are connected by a synapse. Weighted, directed graphs can be searched for an optimal path between any pair of nodes with standard algorithms. Here, we are interested in finding the path along which the sum of the synaptic resistances from one cell to another is minimal. Since each cell is a place cell, such a path also corresponds to a path in two-dimensional space. Our basic finding is that minimizing the sum of the synaptic resistances along a path in neural space yields the shortest (optimal) path in unobstructed two-dimensional space, so long as the connectivity of the network is great enough. Zn addition to being able to find geodesics in unobstructed space, the same network enables solutions to the ''detour'' and ''shortcut'' problems, in which it is necessary to find an optimal path around a newly introduced barrier and to take a Shorter path through a hole opened up in a preexisting barrier, respectively. We argue that the ability to solve such problems qualifies the proposed hippocampal object as a cognitive map. Graph theory thus provides a sort of existence proof demonstrating that the hippocampus contains the necessary information to function as a map, in the sense postulated by others (O'Keefe,J., and L. Nadel. 1978. The Hippocampus as a Cognitive Map. Clarendon Press, Oxford, UK). It is also possible that the cognitive map ping functions of the hippocampus are carried out by parallel graph searching algorithms implemented as neural processes. This possibility has the great attraction that the hippocampus could then operate in much the same way to find paths in general problem space; it would only be necessary for pyramidal cells to exhibit a strong nonpositional firing correlate.},
	year = {1996},
	eissn = {1540-7748},
	pages = {663-694}
}

@article{MTMT:2941574,
	title = {INTRACELLULAR CORRELATES OF HIPPOCAMPAL THETA-RHYTHM IN IDENTIFIED PYRAMIDAL CELLS, GRANULE CELLS, AND BASKET CELLS},
	url = {https://m2.mtmt.hu/api/publication/2941574},
	author = {YLINEN, A and Soltesz, Ivan and BRAGIN, A and PENTTONEN, M and Sík, Attila and BUZSAKI, G},
	doi = {10.1002/hipo.450050110},
	journal-iso = {HIPPOCAMPUS},
	journal = {HIPPOCAMPUS},
	volume = {5},
	unique-id = {2941574},
	issn = {1050-9631},
	abstract = {The cellular-synaptic generation of rhythmic slow activity (RSA or theta) in the hippocampus has been investigated by intracellular recording from principal cells and basket cells in anesthetized rats. In addition, the voltage-, coherence-, and phase versus depth profiles were examined by simultaneously recording field activity at 16 sites in the intact rat, during urethane anesthesia, and after bilateral entorhinal cortex lesion. In the extracellular experiments the large peak of theta at the hippocampal fissure was attenuated by urethane anesthesia and abolished by entorhinal cortex lesion. The phase versus depth profiles were similar during urethane anesthesia and following entorhinal cortex lesion but distinctly different in the intact, awake rat. These observations suggest that dendritic currents underlying theta in the awake rat may not be revealed under urethane anesthesia. The frequency of theta-related membrane potential oscillation was voltage-independent in pyramidal neurons, granule cells, and basket cells. On the other hand, the phase and amplitude of intracellular theta were voltage-dependent in all three cell types with an almost complete phase reversal at chloride equilibrium potential in pyramidal cells and basket cells. At strong depolarization levels (less than 30 mV) pyramidal cells emitted calcium spike oscillations, phase-locked to theta. Basket cells possessed the most regular membrane oscillations of the three cell types. All neurons of this study were verified by intracellular injection of biocytin. The observations provide direct evidence that theta-related rhythmic hyperpolarization of principal cells is brought about by the rhythmically discharging basket neurons. Furthermore, the finding that basket cells were also paced by rhythmic inhibitory postsynaptic potentials during theta suggest that they were periodically hyperpolarized by their GABAergic septal afferents. (C) 1995 Wiley-Liss, Inc.},
	keywords = {Animals; Female; CONTAINING NEURONS; hippocampus; RATS; Electric Stimulation; Rats, Sprague-Dawley; Electrophysiology; EEG; Theta; CA1; BEHAVING RAT; MEMBRANE-POTENTIAL OSCILLATIONS; anesthesia; dentate gyrus; Excitatory Amino Acid Antagonists/pharmacology; Theta Rhythm/*drug effects; Membrane Potentials/drug effects/physiology; GABA Antagonists/pharmacology; Neurons/drug effects/*physiology; SOURCE DENSITY ANALYSIS; Pyramidal Cells/drug effects/*physiology; Intracellular recording; Urethane; Dendrites/drug effects/physiology; GENERATORS; freely moving rat; Hippocampus/*cytology/*physiology/ultrastructure; QX-314; interneurons},
	year = {1995},
	eissn = {1098-1063},
	pages = {78-90}
}

@article{MTMT:107532,
	title = {GABA-containing neurons in the septum control inhibitory interneurons in the hippocampus},
	url = {https://m2.mtmt.hu/api/publication/107532},
	author = {Freund, Tamás and Antal, Miklós},
	doi = {10.1038/336170a0},
	journal-iso = {NATURE},
	journal = {NATURE},
	volume = {336},
	unique-id = {107532},
	issn = {0028-0836},
	keywords = {Animals; RATS; Interneurons/physiology; Hippocampus/cytology/*physiology; gamma-Aminobutyric Acid/*physiology; Neural Inhibition; Afferent Pathways/physiology; Septum Pellucidum/cytology/*physiology; Neurons, Afferent/cytology/physiology},
	year = {1988},
	eissn = {1476-4687},
	pages = {170-173}
}