Afterpotential characteristics and firing patterns in maturing rat hippocampal CA1 neurones in in vitro slices.
The postnatal evolution of depolarizing after-potentials (DAPs) and after-hyperpolarizations (AHPs) was studied in rat CA1 hippocampal neurones (5-68 days of age) using in vitro slices. Results were pooled into 4 age groups: P5-9, P10-16, P17-24 and P26-68. In P5-9 cells, DAPs were seen as passive signals, with a time constant similar to the time constant of the membrane. The evolution of the DAP was characterized by a decrease in amplitude, an increase in duration and a change in contour. In P10-16 and P17-24 cells, the DAPs often had a plateau or a hump-like shape which increased the probability of firing and the occurrence of spike doublets. The firing pattern and bursting behaviour of P10-16 CA1 neurones differed from the pattern typical of the adult. P5-9 and P10-16 cells had post-burst AHPs with a smaller amplitude and a more prolonged early phase than at late stages of development.
Costa
P F
PF
Departamento de Fisiologia, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Portugal.
Ribeiro
M A
MA
Santos
A I
AI
D000200:Action Potentials; D000375:Aging / Q000502:physiology*; D000818:Animals; D004594:Electrophysiology; D005260:Female; D006624:Hippocampus / Q000166:cytology / Q000254:growth & development / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D009474:Neurons / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D011930:Reaction Time