Table 1.

Various electrophysiological parameters recorded from Δ⁹-THC withdrawn, both spontaneous (S-W) and induced (P-W), and vehicle-treated (CTRL) rats

	No. of cells	Cells/track	Firing rate, Hz	Burst rate, burst/sec	Spikes/burst
CTRL	142	0.99  ± 0.06	3.2  ± 0.07	0.33  ± 0.02	3.26  ± 0.05
S-W	96	1.2  ± 0.08	2.05  ± 0.07**	0.14  ± 0.02**	2.62  ± 0.07*
P-W	90	1.12  ± 0.05	1.68  ± 0.04**	0.13  ± 0.01**	2.15  ± 0.09**

Cells/track, number of cells responding to antidromic identification from nucleus accumbens divided by the number of tracks; firing rate, number of spikes per second, Hz; burst rate, number of bursts averaged for 1 sec; spikes/burst, number of action potentials per each burst. Statistical analysis (ANOVA + Newman–Keuls’ test) revealed that Δ⁹-THC withdrawn rats showed a reduced spontaneous activity in terms of firing rate [F(2,35) = 16.53, **P < 0.01], burst firing [F(2,35) = 7.06; **P < 0.01] and spikes/burst [F(2,35) = 8.28; *P < 0.05, **P < 0.01].