Spontaneous firing rate of lateral septal neurons decreases after forced swimming test in Wistar rat

The systemic or local administration of diverse antidepressants increases the neuronal firing rate of the lateral septal nucleus (LSN), whereas some stressful situations decrease its firing rate; however, any long-lasting effect exerted by the forced swimming (FS) test (15-min pretest and 5-min test 24 h later) on the firing rate of the LSN is unknown. Therefore, single-unit extracellular recordings were obtained from the LSN neurons of control rats (Ctrl, n=6) and FS rats ( n=10) 2 h after the last swimming session. In other rats, spontaneous firing rate of cortical neurons was recorded under the same experimental conditions. The firing rate of the LSN neurons of the animals in the FS group was significantly lower (9.2±1.7 spikes/10 s; P