Genetic effects in a progressive model of parkinsonism induced by reserpine.

OBJECTIVE AND METHODS: We investigated the locomotor, emotional, physiological, and neurobiological effects induced by low-dose reserpine repeated treatment (0.1 mg/kg; 14 injections) in males from the Lewis (LEW), Spontaneously Hypertensive Rats (SHR), and SHR.LEW-(D4Rat76-D4Mgh11) (SLA16) isogenic rat strains, which have different genetic backgrounds on chromosome 4. Behavioral responses in the catalepsy, open-field, and oral movements' tests were coupled with blood pressure, body weight, and striatal tyrosine hydroxylase (TH) level assessments to establish neurobiological comparisons between reserpine-induced impairments and genetic backgrounds RESULTS: Results revealed the SHR strain was more sensitive in the catalepsy test and exhibited higher TH immunoreactivity in the dorsal striatum. The SLA16 strain presented more oral movements, suggesting increased susceptibility to develop oral dyskinesia. CONCLUSIONS: Our results showed the efficacy of repeated treatment with a low dose of reserpine and demonstrated, for the first time, the genetic influence of a specific region of chromosome 4 on the expression of these effects.

Patterns of c-Fos expression in telencephalic areas of Tropidurus hygomi (Iguania: Tropiduridae) exposed to different social contexts.

Social behavior in lizards contributes to understanding biological standards and provides models for structuring research about neural mechanisms. Studies have confirmed the effectiveness of comparative models and evidence has contributed to clarifying adult brain plasticity phenomenon when exposed to different stimuli. The expression of c-Fos has been widely used to identify brain areas involved in different behavioral stimuli. The purpose of the present study was to map the expression of c-Fos protein in different telencephalic areas of the lizard Tropidurus hygomi after they were exposed to visual stimuli with another individual of the same species in different social contexts. Lizards were allocated to one of four groups: 1) control group (CTL) - males not exposed to any other animal; 2) exposure to juvenile (EJU) - males exposed to a juvenile; 3) exposure to male (EMA) - males exposed to another adult male; and 4) exposure to females (EFE) -males exposed to female. The EFE group exhibited a greater number of c-Fos + cells in cortical areas (medial cortex - MC and dorsomedial cortex - DMC) and in amygdala (AMY), showing a possible relationship between these structures and behavioral components. Studies like this can contribute significantly to a better understanding of neurophysiological, behavioral, and evolutive aspects.