Sedation and disruption of maternal motivation underlie the disruptive effects of antipsychotic treatment on rat maternal behavior

Abstract

The behavioral mechanisms underlying antipsychotic-induced maternal behavior deficits were examined in the present study. Different groups of postpartum rats were treated with haloperidol (0.1 mg/kg), clozapine (10.0 mg/kg), chlordiazepoxide (5.0 mg/kg, an anxiolytic) or vehicle (0.9% saline) on Days 4 and 6 postpartum and their maternal behaviors were tested under either pup-separation (e.g. pups were removed from their mothers for 4 h before testing) or no-pup-separation condition. Maternal behavior and drug-induced sedation were further tested for 3 days from Day 8 to 12 postpartum. Results show that pup-separation, which putatively increases maternal motivation, did significantly shorten clozapine-elongated pup approach latency, increase pup licking and nursing but fail to reverse the deficits in pup retrieval and nest building in the lactating rats treated with haloperidol and clozapine. Repeated haloperidol treatment produced a progressively enhanced disruption on pup retrieval and nest building and an attenuated sedation. In contrast, clozapine showed a progressively diminished disruption on pup retrieval and a concomitantly diminished sedative effect. Based on these findings, we suggest that antipsychotic drugs disrupt active maternal responses at least in part by suppressing maternal motivation, and drug-induced sedation also contributes to this disruptive effect, especially with clozapine.

Effects of 5-hydroxytryptamine 2C receptor agonist MK212 and 2A receptor antagonist MDL100907 on maternal behavior in postpartum female rats

“…The basic procedure was similar to what has been described in Zhao and Li (Zhao and Li, 2009a). Briefly, starting two or three days before the first possible expected parturition date, the subjects were monitored every day for signs of parturition.…”

Antipsychotic drugs on maternal behavior in rats

“…To directly address the motivational versus motoric issue, we employed a pup-separation technique (Zhao and Li, 2009c). Previous work shows that removing pups from dams for several hours (>3 h) prior to maternal tests can significantly increase a mother rat’s maternal motivation and stimulate dopamine release in the ventral striatum of maternal rats (Hansen et al , 1993; Hansen, 1994).…”

Erken Yavru Kayıplarının Sıçanlardaki Annelik Davranışına ve Sonraki Yavrulara Etkileri: Bebek Kaybının Hayvan Çalışması Modeli

“…In contrast to this finding, Pryce and Feldon revealed that early deprivation for 4 hours led to a marked increase in licking and arched-back nursing of the pups (29). Their findings were supported by Marmendal et al and Zhao & Ming who also suggested that enhanced maternal behavior in response to pup-separation served as a 'compensatory' mechanism for deprivation (30,31).…”