Haloperidol differentially potentiates tonic immobility, the dorsal immobility response, and catalepsy in the developing rat

Publisher Website
Google Scholar
Abstract
The effects of a single subcutaneous injection of haloperidol (1 or 10 mg/kg) or the vehicle solution on three kinds of behavioral inhibition were investigated in rats of 10, 15, and 20 days of age. The behaviors measured were tonic immobility, a response induced by lacing an animal on its back supported by a V‐shaped trough; the dorsal immobility response, which can be elicited in young rodents by grasping the skin of the dorsal surface of the neck and lifting the animal into the air; and catalepsy, a form of immobility in which animals remain in unusual postures but are capable of righting themselves, and which can be elicited by drugs which block dopamine receptors. Haloperidol (10 mg/kg) significantly potentiated the duration of tonic immobility only at 10 days of age; potentiated catalepsy at all age levels, but significantly less in the 15‐day‐old rats than in the 10‐ or 20‐day‐old rats; and potentiated the duration of the dorsal immobility response in the 10‐ and 20‐day‐old animals but not in the 15‐day‐olds. These results are discussed with respect to the development of neurotransmitter systems in the brain.