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LEAO, R. N.

Publications and source records attributed to LEAO, R. N..

2 recordsLinked to original sources

Single-dose DMT reverses anhedonia and cognitive deficits via restoration of neurogenesis in a stress-induced depression model.

Major depressive disorder (MDD) remains a leading cause of disability worldwide, with current treatments limited by delayed onset and low efficacy. The serotonergic psychedelic N,N-dimethyltryptamine (DMT) has shown rapid antidepressant effects in early clinical studies, yet its mechanisms and efficacy remain poorly characterized in established models of depression. Here, we evaluated the effects of a single dose of DMT in the Chronic Unpredictable Mild Stress (UCMS) paradigm, a robust mouse model recapitulating key features of MDD, including anhedonia and cognitive impairment. DMT administered after UCMS reversed depressive-like behavior and restored cognitive performance, outperforming chronic fluoxetine across most domains. When administered during the stress period, DMT prevented the development of anhedonia but did not rescue cognitive deficits, suggesting partial protection. Notably, DMT remained effective under isoflurane anesthesia, indicating that its therapeutic action can occur independently of the psychedelic experience. Histological analyses revealed that all DMT regimes significantly increased adult-born granule cell (abGC) integration and reduced the number of ectopically abnormally integrated abGCs. Together, our findings highlight the robust and multifaceted effects of DMT on behavior and neurogenesis, positioning it as a promising candidate for rapid-acting antidepressant strategies that target structural circuit repair.

neuroscience↗

Auditory regulation of hippocampal locomotion circuits by a non-canonical reticular-limbic pathway

The ability to rapidly detect and respond to unexpected auditory stimuli is critical for adaptive behavior, especially during locomotion. Since movement suppresses auditory cortical activity, it remains unclear how salient auditory information influences locomotor circuits. In this work, using in vivo calcium imaging, electrophysiology, chemo- and optogenetics, we investigate the path that relays loud broadband sounds to the dorsal hippocampus (dHPC) and modulates theta oscillations. We demonstrate that noise accelerates theta frequency and decreases its power, effects mediated by entorhinal cortex (EC) and medial septum (MS) inputs while independent of the primary auditory cortex. Activation of dorsal cochlear nucleus (DCN) neurons projecting to the pontine reticular nucleus (PRN) mimics noise-driven hippocampal responses, supporting a brainstem-limbic auditory processing route. Furthermore, noise selectively modulates CA1 pyramidal neuron and interneuron activity, reflecting diverse circuit dynamics. Finally, loud broadband noise stimulus increased theta coherence between the dHPC and the medial prefrontal cortex (mPFC), enhancing interregional synchronization. These results highlight the mechanisms in which the DCN filters behaviorally relevant sounds promoting acoustic motor integration in the hippocampus during locomotion, without direct influence of the auditory cortex.

neuroscience↗