Scopolamine effects on ultrasonic vocalization emission and behavior in the neonatal mouse.
Developmental alterations of the cholinergic system can lead to short- and long-term detrimental consequences for brain function. In order to study the cholinergic modulation of behavior in the neonatal mouse, we characterized ultrasonic vocalizations and spontaneous behavior of 5- and 8-day old CD-1 Swiss mice after i.p. administration of the muscarinic antagonist scopolamine (doses, 0.8 and 2 mg/kg) during both a first isolation of 30 min and a re-isolation of 5 min, occurring immediately after a brief reunion with the mother. As concerns the first isolation, on PND 5, only scopolamine 0.8m g/kg increased the number of ultrasonic vocalizations and, on PND 8, both doses increased it in a dose-dependent fashion. Scopolamine effects on spontaneous behavior were very limited on PND 5, but markedly evident on PND 8, the high dose increasing activity profile. Independently from treatment, the brief reunion with the mother had no effects on mouse ultrasound emission during re-isolation. The present results show that the cholinergic system plays a role in inhibiting rodent pup USV emission and spontaneous behavior and suggest that the analysis of spontaneous behavior and, in particular, of the number of ultrasonic vocalizations represents a valuable tool to detect precocious developmental alterations of the cholinergic function in the mouse, the most used animal species to model human health disorders.
Branchi
Igor
I
Section of Behavioral Pathophysiology, Laboratorio Fisiopatologia di Organo e di Sistema, Istituto Superiore di Sanità, Viale Regina Elena, 299, 00161 Roma, Italy. branchi@iss.it
Campolongo
Patrizia
P
Alleva
Enrico
E
D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal / Q000187:drug effects*; D001831:Body Temperature / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005106:Exploratory Behavior / Q000187:drug effects; D007103:Immobilization / Q000502:physiology; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D018727:Muscarinic Antagonists / Q000494:pharmacology; D012601:Scopolamine / Q000494:pharmacology*; D012934:Social Isolation; D013997:Time Factors; D014465:Ultrasonics; D014828:Vocalization, Animal / Q000187:drug effects* / Q000502:physiology
D018727:Muscarinic Antagonists; D012601:Scopolamine