Table 1Effects of serotonin and (±)-8-hydroxy-dipropylaminotetralin hydrobromide on hilar neurons
Type HN
n
RMP (mV)
Rin (MΩ)
fAHP (mV)
Rectific.
5-HT
8-OH-DPAT
MP
Rin
sAHP
MP
Rin
sAHP
I
15
−68±1.4
89±7
11±1
0.75±0.03
↓
↓
↓
↓
↓
=
I
10
−65±1.2
86±10
12±1
0.68±0.05
=↑
=↑
↓
=
=
=
II
7
−69±3.3
88±11
6±2
1.1±0.08
↓
↓
↓
↓
↓
=
n, number of cells; RMP, resting membrane potential; Rin, apparent input resistance; fAHP, fast afterhyperpolarization following a single action potential; rectification was determined by dividing voltage responses to depolarizing current pulses by responses to hyperpolarizing current pulses of the same amplitude (0.2 to 0.3nA); effects on membrane potential (MP): ↓, hyperpolarization, ↑, depolarization; effects on input resistance (Rin): ↓, decrease, ↑, increase; effects on slow afterhyperpolarization (sAHP): ↓, reduction in amplitude; 5-HT (40μM) was applied to all cells; 8-OH-DPAT (1–2μM) was applied to 10 out of 15 type I neurons (cells hyperpolarized by 5-HT), seven out of 10 type I neurons (cells not hyperpolarized by 5-HT) and to all type II hilar neurons.
