title: Changes of activity of cortical neurons induced by acetylcholine in adult and young rats.
abstract: Acetylcholine was applied microiontophoretically by means of multibarrel electrodes to neurons in the sensorimotor cortex of adult, 18-, 15-, 12-, and 9-day-old rats anesthetized with urethane. A total of 229 neurons was recorded; only 22 of them were in 18- and 15-day-old rats because of similarity of results with those from adult as well as 12-day-old animals. In adult rats 43 of 58 neurons recorded in infragranular layers responded to acetylcholine with a marked increase in their firing. In 12-day-old rats the incidence of excitatory responses to acetylcholine was also high: 59 of 86 cells again were localized predominantly in deep cortical layers (V and VI). A marked difference was observed in 9-day-old rats: only 15 of 63 neurons were excited by acetylcholine. A majority of cells did not respond at all--including units localized in infragranular layers. Two cells in layer V responded to acetylcholine by an inhibition. Our results indicate that there is a marked increase in cholinoceptivity of cortical neurons between postnatal days 9 and 12. This finding is in agreement with the finding that local application of acetylcholine can elicit an epileptogenic focus in 12-day but not in 9-day-old rat pups.
authors: Institute of Physiology, Czechoslovak Academy of Sciences, Prague.
authors: A
authors: A
authors: Strejcková
authors: P
authors: P
authors: Mares
authors: V
authors: V
authors: Raevsky
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000375:Aging; D000818:Animals; D002415:Cats; D002540:Cerebral Cortex / Q000187:drug effects / Q000502:physiology; D008297:Male; D009044:Motor Cortex / Q000187:drug effects* / Q000502:physiology; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D011712:Pyramidal Tracts / Q000187:drug effects / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D011950:Receptors, Cholinergic / Q000187:drug effects / Q000502:physiology
chemical_list: D011950:Receptors, Cholinergic; D000109:Acetylcholine