Disrupted excitation-inhibition (E/I) balance involving GABA and glutamate (Glu) is implicated in the pathophysiology of depression. Ketamine, an NMDA receptor antagonist with rapid antidepressant properties, may modulate this balance, yet proton magnetic resonance spectroscopy (¹H-MRS) studies report inconsistent findings regarding the direction, magnitude, and timing of neurochemical effects....
Chronic stress disrupts glutamatergic and GABAergic plasticity in the medial prefrontal cortex (mPFC), impairing circuit integration and contributing to the pathophysiology of stress-related disorders, such as Major Depressive Disorder (MDD). Rapid-acting antidepressants like ketamine can rapidly reverse these deficits, but its clinical use is limited by psychotomimetic side effects. Notably,...
Major depressive disorder (MDD) is associated with disruptions in glutamatergic and GABAergic activity in the medial prefrontal cortex (mPFC), leading to altered synaptic formation and function. Low doses of ketamine rapidly rescue these deficits, inducing fast and sustained antidepressant effects. While it is suggested that ketamine produces a rapid glutamatergic enhancement in the mPFC, the...
Depression is a multifactorial syndrome with a variety of underlying pathological mechanisms. While ketamine, an N-methyl-D-aspartate receptor (NMDAR) antagonist, exhibits a rapid antidepressant action in the central never system (CNS), the potential addiction and psychotomimetic adverse effects of ketamine limit its chronic use in clinical practice. Therefore, it is necessary to discover an...
Behavioural PharmacologyJune 1, 2023Débora A E Colodete, Nicole R Silva, João Francisco C Pedrazzi et al.
Cannabidiol is a phytocannabinoid that lacks the psychotomimetic properties of Δ9-tetrahydrocannabinol (THC), the main psychoactive Cannabis sativa component. Cannabidiol has several potential therapeutic properties, including anxiolytic, antidepressant, and antipsychotic; however, cannabidiol has low oral bioavailability, which can limit its clinical use. Here, we investigated if two...
The pathophysiology and treatment of depression have been the focus of intense research and while there is much that remains unknown, modern neurobiological approaches are making progress. This work demonstrates that stress and depression are associated with atrophy of neurons and reduced synaptic connectivity in brain regions such as the hippocampus and prefrontal cortex that contribute to...
Dysfunction of medial prefrontal cortex (mPFC) in association with imbalance of inhibitory and excitatory neurotransmission has been implicated in depression. However, the precise cellular mechanisms underlying this imbalance, particularly for GABAergic transmission in the mPFC, and the link with the rapid acting antidepressant ketamine remains poorly understood. Here we determined the...
Significance A metabolite of ketamine, (2 R ,6 R )-hydroxynorketamine [(2 R ,6 R )-HNK], produces rapid and sustained antidepressant effects in animal models but without the side effects of ketamine. Notably, (2 R ,6 R )-HNK does not block the NMDA receptor, the primary target of ketamine. Here, we demonstrate that the antidepressant effects of (2 R ,6 R )-HNK require activity dependent release...
Beneficial effects of cannabidiol (CBD) have been described for a wide range of psychiatric disorders, including anxiety, psychosis, and depression. The mechanisms responsible for these effects, however, are still poorly understood. Similar to clinical antidepressant or atypical antipsychotic drugs, recent findings clearly indicate that CBD, either acutely or repeatedly administered, induces...