Prepulse inhibition of the acoustic startle reflex impairment by 5-HT2A receptor activation in the inferior colliculus is prevented by GABAA receptor blockade in the pedunculopontine tegmental nucleus.

The relationship between serotonin dysfunction and schizophrenia commenced with the discovery of the effects of lysergic acid diethylamide (LSD) that has high affinity for 5-HT receptors. Activation of these receptors produces perceptual and behavioural changes such as illusions, visual hallucinations and locomotor hyperactivity. Using prepulse inhibition (PPI) of the acoustic startle, which is impaired in schizophrenia,we aimed to investigate:i) the existence of a direct and potentially inhibitory neural pathway between the inferior colliculus (IC) and the pedunculopontine tegmental nucleus (PPTg) involved in the mediation of PPI responses by a neural tract tracing procedure;ii) if the microinjection of the 5-HT receptors agonist DOI in IC would activate neurons in this structure and in the PPTg by a c-Fos protein immunohistochemistry study;iii) whether the deficits in PPI responses, observed after the administration of DOI in the IC, could be prevented by the concomitant microinjection of the GABA receptor antagonist bicuculline in the PPTg.

The influence of early exposure to methylphenidate on addiction-related behaviors in mice.

Methylphenidate (MET) has a putative cognitive enhancer effect that has led adolescents and young adults to increase and indiscriminate its use aiming to ameliorate their productivity. However, the impacts of MET on addiction-related behaviors, emotional levels, and cognition are still not fully understood. To investigate the influence of chronic treatment with MET during adolescence on addiction-like behaviors, memory, and anxiety in adult mice.