Table 2Effects of serotonin and (±)-8-hydroxy-dipropylaminotetralin hydrobromide on Cl-inhibitory postsynaptic potentials in granule cells
(μM)
Change in the frequency of IPSPs % control (n)
Δ MP (mV)
% Rin
increase
decrease
no effect
5-HT
KCl-electrode
5
130±25 (2)
48±6 (3)
(2)
−5.7±1.2
75±2
40
180±35 (3)
57±8 (3)
(1)
−8.3±1.2
68±3
CsCl-electrode
5
150±23 (5)
44±8 (3)
(1)
2.2±1.0
76±5
40
480±150 (6)
50±10 (3)
(0)
3.5±2.0
70±6
8-OH-DPAT
2
(0)
61±5 (12)
(1)
−9.2±2
73±5
5-HT+5-HT1A receptor antagonists
5
147±11 (7)
(0)
(5)
2±1
90±5
40
149±19 (11)
(0)
(1)
3±1.5
82±6
5-HT was applied to seven granule cells recorded with KCl-filled electrodes and to nine cells recorded with CsCl-filled electrodes under standard conditions (CNQX 10μM and CGP37849 1μM), 5 and 40μM 5-HT were tested in each cell. The 5-HT1A receptor antagonists were: (+) WAY 100135 (5–10μM; six cells) and spiperone (5μM; six cells). The effect on IPSPs was measured at resting membrane potential for 3-min time-periods. Δ MP=change in resting membrane potential. % Rin=percentage change in input resistance.
