Basal forebrain cholinergic lesions in 7-day-old rats alter ultrasound vocalisations and homing behaviour.

We analysed the effects of 192 IgG-saporin lesions on pnd 7 upon neonatal behavioural responses. Number of ultrasonic vocalisations (USVs) were recorded on pnds 9, 11 and 13. On pnd 13 rats underwent a homing test to measure olfactory orientation towards nest material. 192 IgG-saporin reduced the number of USVs at all ages considered while increasing number of entrancies into the nest area. These data suggest that early damage to the basal forebrain cholinergic nuclei induces significant changes in the rat behavioural repertoire as early as the second-postnatal week.