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Titolo:
Spatiotemporal properties of an evoked population activity in rat sensory cortical slices
Autore:
Wu, JY; Guan, L; Bai, L; Yang, Q;
Indirizzi:
Georgetown Univ, Med Ctr, Dept Physiol & Biophys, Washington, DC 20007 USAGeorgetown Univ Washington DC USA 20007 Biophys, Washington, DC 20007 USA
Titolo Testata:
JOURNAL OF NEUROPHYSIOLOGY
fascicolo: 5, volume: 86, anno: 2001,
pagine: 2461 - 2474
SICI:
0022-3077(200111)86:5<2461:SPOAEP>2.0.ZU;2-U
Fonte:
ISI
Lingua:
ENG
Soggetto:
SHORT-TERM-MEMORY; PRIMATE TEMPORAL CORTEX; HIPPOCAMPUS IN-VITRO; EPILEPTIFORM ACTIVITY; NEOCORTICAL SLICES; NEURONAL CORRELATE; LOCUS-COERULEUS; AUDITORY-CORTEX; BARREL CORTEX; OSCILLATIONS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
67
Recensione:
Indirizzi per estratti:
Indirizzo: Wu, JY Georgetown Univ, Med Ctr, Dept Physiol & Biophys, Res Bldg,WP-26,3900 Reservoir Rd NW, Washington, DC 20007 USA Georgetown Univ Res Bldg,WP-26,3900 Reservoir Rd NW Washington DC USA 20007
Citazione:
J.Y. Wu et al., "Spatiotemporal properties of an evoked population activity in rat sensory cortical slices", J NEUROPHYS, 86(5), 2001, pp. 2461-2474

Abstract

We have examined the spatiotemporal properties of ensemble activity, an evoked all-or-none polysynaptic activity in rat neocortical slices. Ensemble activity occurred in cortical slices bathed in normal artificial cerebrospinal fluid (ACSF) and was evoked by a single electrical shock either to the white matter or directly to the cortical tissue. This activity was seen in slices of somatosensory and auditory cortices; in other cortical areas we have not been able to evoke it. The activity developed 10 to 250 ms poststimulus and lasted 280 +/- 120 ms in local field potential (LFP) recordings. Voltage-sensitive dye imaging showed that this activity was an area of activation 0.8 +/- 0.4 mm wide that propagated slowly (11.4 +/- 6.2 mm/s, n = 60, 6 animals) in the horizontal direction. Due to this propagation, the actual duration in the whole tissue may be longer (similar to 400 ms) than thatrecorded by a single LFP electrode. Ensemble activity produced a low-amplitude optical signal (7-14% of the interictal-like spikes in the same tissue), suggesting a moderate net depolarization of the population. These were very different from hyperexcitable (epileptiform) events in the same tissue that had about 10 times the optical signal amplitude and propagated at 125 /- 24 mm/s (n = 21, 6 animals). On a global spatial scale (similar to0.8 mm wide in layers II-III) ensemble activity had a smooth waveform in voltage-sensitive dye signals (population transmembrane potential). On a local scale, field potential recordings showed large fluctuations with complex oscillations and substantial trial-to-trial variation. This suggests that oscillations in cortical circuits occurred only in small clusters of correlated neurons. Ensemble activity was sensitive to the excitation-inhibition balance of the local network. Antagonists of N-methyl-D-aspartate, alpha -amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, and GABAa receptors, and muscarinic agonists and other modest manipulations such as increasing bath concentration of Mg2+ to 2.5-4 mM (normally at 2 mM), or K+ to 5-7 mM (normally 3 mM), all significantly reduced the probability of evoking the activity. The metabotropic glutamate receptor agonist, aminocyclopentane-1,3-dicarboxylic acid, blocked the activity at a low concentration (10-15 muM), while the antagonist (R,S)-alpha -methyl-4-carboxyphenylglycine had no effect even at high concentration (240 muM). Our data suggest that locally organized neuronal clusters may play a role in the organization of oscillatory activities in the gamma band and may participate in cortical integration/amplification occurring on a scale of similar to1 mm x 300 ms.

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Documento generato il 04/07/20 alle ore 21:03:37