Pharmacological effect of one icv dose of allopregnanolone in the female rat: behavioral profile

PELEGRINA L.; ESCUDERO C.; GARCÍA S.; CABRERA R.; LACONI M.; GIULIANI F.

Brazilian Journal of Biological Sciences

Rede Brasileira de Informações Biológicas

Año: 2015 vol. 2 p. 39 - 50

2358-2731

We have previously observed that intracerebroventricularallopregnanolone (ALLO) injection produced an anxiolytic effect andinhibited sexual receptivity when the test was performed in a separatemanner. Also, ALLO reverts learning deficit in female rats in thehippocampi. To study the behavioral effects of an acute treatmentwith ALLO in the right lateral ventricle we used two approaches: a- Abattery test to analyze the anxiety and mating behavior. And b- Theavoidance test and novel object recognition test to evaluate its effecton memory and learning. Ovariectomized rats were injected withestrogen and progesterone. After it ALLO or vehicle wereadministered into the right lateral ventricle. To reach the objective (a)rats were put in a sequential battery test in the next order: 1-Openfield. 2- Plus maze task. 3- Mating behavior. For the aim (b) it wasperformed a Novel Object Recognition Test and Step-down InhibitoryAvoidance Task. ALLO did not affect locomotors-exploratorybehavior. Animals treated with ALLO spent more time and had moreentries into the open arm in a plus-maze task and lordosis quotientwas lower than in the control group. ALLO increased the latency instep down test and had no effects on the discrimination index test inNORT. Here we demonstrated that one pharmacological dose ofALLO in ovariectomized primed rats is enough to generate allchanges observed in the battery test. Moreover, the acute treatmentwith ALLO in lateral ventricle enhanced the memory acquisition inan avoidance task.