@article{MTMT:2966606,
	title = {Synaptic GABA(A) activation inhibits AMPA-kainate receptor-mediated bursting in the newborn (P0-P2) rat hippocampus.},
	url = {https://m2.mtmt.hu/api/publication/2966606},
	author = {Lamsa, Karri and Palva, JM and Ruusuvuori, E and Kaila, K and Taira, T},
	journal-iso = {J NEUROPHYSIOL},
	journal = {JOURNAL OF NEUROPHYSIOLOGY},
	volume = {83},
	unique-id = {2966606},
	issn = {0022-3077},
	abstract = {The mechanisms of synaptic transmission in the rat hippocampus at birth are assumed to be fundamentally different from those found in the adult. It has been reported that in the CA3-CA1 pyramidal cells a conversion of "silent" glutamatergic synapses to conductive alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) synapses starts gradually after P2. Further, GABA via its depolarizing action seems to give rise to grossly synchronous yet slow calcium oscillations. Therefore, GABA is generally thought to have a purely excitatory rather than an inhibitory role during the first postnatal week. In the present study field potential recordings and gramicidin perforated and whole cell clamp techniques as well as K(+)-selective microelectrodes were used to examine the relative contributions of AMPA and GABA(A) receptors to network activity of CA3-CA1 pyramidal cells in the newborn rat hippocampus. As early as postnatal day (P0-P2), highly coherent spontaneous firing of CA3 pyramidal cells was seen in vitro. Negative-going extracellular spikes confined to periodic bursts (interval 16 +/- 3 s) consisting of 2.9 +/- 0.1 spikes were observed in stratum pyramidale. The spikes were accompanied by AMPA-R-mediated postsynaptic currents (PSCs) in simultaneously recorded pyramidal neurons (7.6 +/- 3.0 unitary currents per burst). In CA1 pyramidal cells synchronous discharging of CA3 circuitry produced a barrage of AMPA currents at >20 Hz frequencies, thus demonstrating a transfer of the fast CA3 network activity to CA1 area. Despite its depolarizing action, GABA(A)-R-mediated transmission appeared to exert inhibition in the CA3 pyramidal cell population. The GABA(A)-R antagonist bicuculline hypersynchronized the output of glutamatergic CA3 circuitry and increased the network-driven excitatory input to the pyramidal neurons, whereas the GABA(A)-R agonist muscimol (100 nM) did the opposite. However, the occurrence of unitary GABA(A)-R currents was increased after muscimol application from 0.66 +/- 0.16 s(-1) to 1.43 +/- 0.29 s(-1). It was concluded that AMPA synapses are critical in the generation of spontaneous high-frequency bursts in CA3 as well as in CA3-CA1 transmission as early as P0-P2 in rat hippocampus. Concurrently, although GABA(A)-R-mediated depolarization may excite hippocampal interneurons, in CA3 pyramidal neurons it can restrain excitatory inputs and limit the size of the activated neuronal population.},
	keywords = {Animals; RATS; Electric Stimulation; Action Potentials/drug effects; Rats, Wistar; Animals, Newborn; Hippocampus/*physiology; 6-Cyano-7-nitroquinoxaline-2,3-dione/pharmacology; Synapses/drug effects/*physiology; Patch-Clamp Techniques; Bicuculline/pharmacology; Quinoxalines/pharmacology; Muscimol/pharmacology; Receptors, AMPA/*physiology; Pyramidal Cells/drug effects/*physiology; 2-Amino-5-phosphonovalerate/pharmacology; Interneurons/drug effects/*physiology; Receptors, Kainic Acid/*physiology; Receptors, GABA-A/*physiology; In Vitro Techniques},
	year = {2000},
	eissn = {1522-1598},
	pages = {359-366},
	orcid-numbers = {Lamsa, Karri/0000-0002-4609-1337}
}

@article{MTMT:2966605,
	title = {Fast network oscillations in the newborn rat hippocampus in vitro.},
	url = {https://m2.mtmt.hu/api/publication/2966605},
	author = {Palva, JM and Lamsa, Karri and Lauri, SE and Rauvala, H and Kaila, K and Taira, T},
	doi = {10.1523/JNEUROSCI.20-03-01170.2000},
	journal-iso = {J NEUROSCI},
	journal = {JOURNAL OF NEUROSCIENCE},
	volume = {20},
	unique-id = {2966605},
	issn = {0270-6474},
	abstract = {Spontaneous neural activity is crucial for the formation of the intricate patterns of cortical connectivity during development. In particular, temporal correlations in presynaptic and postsynaptic activity have been hypothesized to be a critical determinant in the selection of neurons that are to become wired together. To date, however, temporally correlated activity in the neonatal brain has been believed to take place with a precision of tens of milliseconds to seconds. Here we describe a novel type of a fast network oscillation associated with millisecond synchronization of pyramidal cell firing in newborn rat hippocampus in vitro. Individual pyramidal neurons fired mainly at lower gamma frequencies (20-40 Hz) but were synchronized into a high-frequency (100-400 Hz) population oscillation that was reflected in field potential spikes and intracellular AMPA-kainate receptor-mediated currents. The high-frequency population oscillation was patterned by a gamma-frequency modulatory oscillation. The gamma modulation was imposed by GABAergic currents, which exerted an inhibitory action on pyramidal neurons. Patterned activity based on GABAergic inhibition and glutamatergic excitation thus occurs already in newborn hippocampus. The network oscillations described here may be a mechanism for selective coincidence detection with a millisecond range temporal precision to shape the patterns of connectivity within the emerging hippocampal synaptic circuitry.},
	keywords = {Animals; RATS; Oscillometry; Pyramidal Cells/physiology; Nerve Net/*physiology; Interneurons/physiology; Hippocampus/cytology/*physiology; Electrophysiology; Time Factors; Rats, Wistar; Neural Inhibition/physiology; Animals, Newborn/*physiology; gamma-Aminobutyric Acid/physiology; Cell Aging; Receptors, AMPA/physiology; In Vitro Techniques; Receptors, Kainic Acid/physiology},
	year = {2000},
	eissn = {1529-2401},
	pages = {1170-1178},
	orcid-numbers = {Lamsa, Karri/0000-0002-4609-1337}
}

@article{MTMT:2966610,
	title = {The K+/Cl- co-transporter KCC2 renders GABA hyperpolarizing during neuronal maturation.},
	url = {https://m2.mtmt.hu/api/publication/2966610},
	author = {Rivera, C and Voipio, J and Payne, JA and Ruusuvuori, E and Lahtinen, H and Lamsa, Karri and Pirvola, U and Saarma, M and Kaila, K},
	doi = {10.1038/16697},
	journal-iso = {NATURE},
	journal = {NATURE},
	volume = {397},
	unique-id = {2966610},
	issn = {0028-0836},
	abstract = {GABA (gamma-aminobutyric acid) is the main inhibitory transmitter in the adult brain, and it exerts its fast hyperpolarizing effect through activation of anion (predominantly Cl-)-permeant GABA(A) receptors. However, during early neuronal development, GABA(A)-receptor-mediated responses are often depolarizing, which may be a key factor in the control of several Ca2+-dependent developmental phenomena, including neuronal proliferation, migration and targeting. To date, however, the molecular mechanism underlying this shift in neuronal electrophysiological phenotype is unknown. Here we show that, in pyramidal neurons of the rat hippocampus, the ontogenetic change in GABA(A)-mediated responses from depolarizing to hyperpolarizing is coupled to a developmental induction of the expression of the neuronal (Cl-)-extruding K+/Cl- co-transporter, KCC2. Antisense oligonucleotide inhibition of KCC2 expression produces a marked positive shift in the reversal potential of GABAA responses in functionally mature hippocampal pyramidal neurons. These data support the conclusion that KCC2 is the main Cl- extruder to promote fast hyperpolarizing postsynaptic inhibition in the brain.},
	keywords = {Animals; RATS; Guinea Pigs; Electrophysiology; gamma-Aminobutyric Acid/*physiology; Cell Differentiation; RNA, Messenger/analysis; Gene Expression Regulation, Developmental; reverse transcriptase polymerase chain reaction; Potassium/metabolism; Blotting, Southern; Chlorides/metabolism; GABA Agonists/pharmacology; Muscimol/pharmacology; *Symporters; In Vitro Techniques; Pyramidal Cells/cytology/drug effects/*physiology; Hippocampus/cytology/embryology/metabolism; Carrier Proteins/biosynthesis/genetics/*physiology},
	year = {1999},
	eissn = {1476-4687},
	pages = {251-255},
	orcid-numbers = {Lamsa, Karri/0000-0002-4609-1337}
}

@article{MTMT:2941567,
	title = {Slow kinetics of miniature IPSCs during early postnatal development in granule cells of the dentate gyrus},
	url = {https://m2.mtmt.hu/api/publication/2941567},
	author = {Hollrigel, GS and Soltesz, Ivan},
	journal-iso = {J NEUROSCI},
	journal = {JOURNAL OF NEUROSCIENCE},
	volume = {17},
	unique-id = {2941567},
	issn = {0270-6474},
	abstract = {Whole-cell patch-clamp recordings were used to investigate the properties of GABA(A) receptor-mediated postsynaptic currents during development in dentate gyrus granule cells from neonatal [postnatal day 0 (P0)] to adult rats in brain slices, The frequency of miniature lPSCs (mlPSCs) was low at birth and increased progressively with age, The mlPSCs of all ages could be satisfactorily fitted with the sum of a single exponential rise and single exponential decay, From P0 to P14, both the rise time and the decay time constants were significantly longer than in the adult. The mlPSC rise and decay kinetics did not change during the first 2 postnatal weeks, but during the third week the kinetics sped up and by P21 attained adult values, In contrast, the amplitude of the mlPSCs did not change during development, The synaptic GABA(A) receptors in immature and adult cells showed differential sensitivity to modulators. The subunit-specific benzodiazepine agonist zolpidem increased the decay time constant of the lPSCs of immature granule cells with a reduced potency compared with the adult, Furthermore, zinc decreased the amplitude and decay time constant of mlPSCs from developing granule cells, whereas it had no effect on mlPSCs in adult neurons. The results reveal for the first time that until the end of the second postnatal week the synaptic GABA(A) receptor-mediated currents in dentate granule cells display slower rise and decay kinetics but similar amplitudes compared with adult, resulting in a net decrease in synaptic charge transfer during development.},
	keywords = {INHIBITION; SUBUNIT; GAMMA-AMINOBUTYRIC-ACID; ION CHANNELS; ZINC; Development; zolpidem; dentate gyrus; GABAERGIC NEURONS; Pyramidal Neurons; GABA(A) receptor; LOCAL-CIRCUIT NEURONS; GABA-A receptor; SUBUNIT MESSENGER-RNAS; DELTA-SUBUNIT; RAT HIPPOCAMPAL-FORMATION; INHIBITORY POSTSYNAPTIC CURRENTS},
	year = {1997},
	eissn = {1529-2401},
	pages = {5119-5128}
}

@article{MTMT:107599,
	title = {Precision and variability in postsynaptic target selection of inhibitory cells in the hippocampal CA3 region},
	url = {https://m2.mtmt.hu/api/publication/107599},
	author = {Gulyás, Attila and Miles, R and Hájos, Norbert and Freund, Tamás},
	doi = {10.1111/j.1460-9568.1993.tb00240.x},
	journal-iso = {EUR J NEUROSCI},
	journal = {EUROPEAN JOURNAL OF NEUROSCIENCE},
	volume = {5},
	unique-id = {107599},
	issn = {0953-816X},
	year = {1993},
	eissn = {1460-9568},
	pages = {1729-1751},
	orcid-numbers = {Gulyás, Attila/0000-0003-4961-636X}
}