Neuroscience
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Affective disorders (i.e. anxiety and depression) are commonly observed in patients with epilepsy and induce seizure aggravation. Animal models of epilepsy that exhibit affective disorder features are essential in developing new neuromodulatory treatments. GEAS-W rats (Generalized Epilepsy with Absence Seizures, Wistar background) are an inbred model of generalized epilepsy showing spontaneous spike-wave discharges concomitant with immobility. ⋯ We observed a main effect of treatment and a significant treatment by strain interaction on anxiety-like and depressive-like behaviours, with active-tDCS GEAS-W rats entering the center of the open field more often and showing less immobility in the forced swimming test. Furthermore, there was a main effect of treatment on corticosterone with active-tDCS animals showing marked reduction in plasmatic levels. This study described preclinical evidence to support tDCS treatment of affective disorders in epilepsy and highlights corticosterone as a possible mechanism of action.
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The role of normal sensory inputs in the development of sensory cortices is well known, however, their impacts on the hippocampus, an integrator of sensory modalities with important roles in cognitive functions, has received much less attention. Here, we applied a long-term sensory deprivation paradigm by trimming the rats' whiskers bilaterally, from postnatal day 3 to 59. Female sensory-deprived (SD) rats showed more on-wall rearing and visits to the center of the open-field box, shorter periods of grooming, less defecation and less anxiety-like behaviors in the elevated plus-maze compared to controls, who had their intact whiskers brushed. ⋯ Sholl analysis of CA3 neurons in SD animals also disclosed significantly more branched apical dendrites in males and basal dendrites in females. Sensory deprivation also led to a considerable spine loss and variation of different spine types in a sex-dependent manner. Our findings suggest that experience-dependent structural plasticity is capable of spreading far beyond the manipulated sensory zones and the inevitable functional alterations can be expressed in a multifactorial sex-dependent manner.