Frontiers in Behavioral Neuroscience
January 1, 2011
Alessandra Paparelli, Marta Di Forti, Paul D. Morrison et al.
217 citations
Schizophrenia is best understood as a syndrome rather than a single disease, with high heritability and multiple genetic and environmental factors pushing individuals over a threshold into clinical expression. Evidence that certain drugs can induce schizophrenia-like psychosis has been neglected as an environmental factor. Over the past 60 years, understanding the link between drug abuse and psychosis has shaped the modern view that liability to psychosis, including schizophrenia, is distributed continuously through the general population, similar to hypertension and diabetes. This review examines hypotheses arising from the association between common psychotomimetic drugs (LSD, amphetamines, cannabis, phencyclidine) and schizophrenia.
Frontiers in Behavioral Neuroscience
October 9, 2018
Yu Yang, Weina Ju, Haining Zhang et al.
80 citations
Mice exposed to chronic social defeat stress showed reduced spatial working memory and contextual fear memory, along with decreased levels of the NMDA receptor subunit NR2B, reduced long-term potentiation, and smaller NMDA receptor-mediated currents in the hippocampus. Ketamine treatment reversed these memory deficits and increased NR2B expression, LTP, and NMDA receptor-mediated currents. The findings suggest that depression-related memory dysfunction involves downregulation of hippocampal NR2B and synaptic plasticity, and that ketamine's antidepressant effects include restoring these measures.
Frontiers in Behavioral Neuroscience
May 16, 2014
Lukáš Rambousek, Tomáš Páleníček, Karel Valeš et al.
55 citations
Psilocin, the main metabolite of psilocybin and an agonist at 5-HT2A receptors, dose-dependently impaired spatial learning and memory retrieval in rats but did not affect memory consolidation. In the Carousel maze, both 1 and 4 mg/kg doses significantly impaired acquisition, with the higher dose blocking learning even in a subsequent saline session. In the Morris water maze, only the 4 mg/kg dose disrupted reinforced retrieval; the lower dose had no effect. Neither dose impaired memory consolidation when injected post-training. These findings suggest that 5-HT2A receptor activation disrupts certain cognitive processes relevant to schizophrenia models, though the validity of such animal models remains questioned due to the complexity of human cognition.
Frontiers in Behavioral Neuroscience
April 16, 2018
André Schwertner, Maxciel Zortéa, Felipe Vasconcelos Torres et al.
48 citations
Subanesthetic doses of ketamine alter cortical responses to sensory stimuli, as measured by event-related potentials (ERPs). A systematic review of 18 studies found that ketamine reduces certain ERP components (N2, P2, P3 amplitudes, PN, and MMN) while leaving others stable or increased (P50 reduction, PPI, P1, and N1 amplitudes). These changes suggest ketamine modifies how the brain perceives contrast between visual and auditory stimuli. The analgesic effect may stem from decreased affective discrimination of sensory information, a finding from schizophrenia research that also informs treatment of mood disorders, pain, and ketamine abuse.
Frontiers in Behavioral Neuroscience
July 28, 2017
Robson Savoldi, Daniel Polari, Jaquelinne Pinheiro‐da‐silva et al.
38 citations
Ayahuasca, a traditional Amazonian infusion of Banisteriopsis caapi and Psychotria viridis, contains the hallucinogen DMT and monoamine oxidase inhibitors. In adult zebrafish, low concentrations (0.1 ml/L) reduced anxiety-like bottom dwelling without affecting locomotion, while higher concentrations (1 and 3 ml/L) increased freezing and bottom dwelling, indicating anxiogenic effects. Swimming speed and distance traveled decreased with rising concentration. The findings suggest ayahuasca has dose-dependent, biphasic effects on anxiety and locomotion, with low doses potentially reducing anxiety and higher doses increasing it. Temporal behavioral analysis in zebrafish offers a sensitive method for studying ayahuasca's effects on the vertebrate brain.
Frontiers in Behavioral Neuroscience
June 23, 2021
A. Wilkowska, Ł. Szałach, W. Cubała
32 citations
Major depressive disorder is the leading cause of disability worldwide, and its pathophysiology remains incompletely understood. The gut microbiome, acting through the gut–microbiota–brain axis, is an increasingly recognized environmental factor in depression. Available treatments are insufficient, as 30% of patients are treatment-resistant, creating a need for novel strategies. Ketamine is an effective antidepressant in treatment-resistant patients, and its effects may be partially mediated by modification of gut microbiota. This review examines data on gut microbiota in depression, focusing on ketamine's effects on the microbiome in animal models. Earlier reports are preliminary and insufficient for firm conclusions, but further studies could clarify the gut–brain axis's role in depression treatment and lead to new strategies.
Frontiers in Behavioral Neuroscience
August 27, 2018
Bruno Lobão‐soares, Paulianny Eduardo-Da-Silva, Hugo Amarilha et al.
15 citations
Ayahuasca, a psychoactive brew containing β-carbolines and DMT, impairs memory and locomotion in zebrafish after chronic (13-day) exposure. In a one-trial object discrimination task, adult zebrafish exposed chronically to 0.1 or 0.5 ml/L ayahuasca showed worse discriminative performance and altered locomotion compared to controls, while acute (single) exposure did not affect memory but the higher concentration reduced locomotion. The findings suggest that chronic ayahuasca use negatively affects mnemonic parameters, reinforcing the zebrafish as a model for psychedelic drug screening.
Frontiers in Behavioral Neuroscience
December 16, 2021
Sophia Khom, Jacques D. Nguyen, Sophia A. Vandewater et al.
12 citations
Female rats that self-administer the entactogen psychostimulants methylone, pentylone, and MDMA escalate their drug intake under extended-access conditions, similar to male rats and typical psychostimulants. Pentylone and methylone led to more infusions than MDMA, and pentylone produced higher breakpoints in progressive ratio testing. In the central amygdala, baseline GABAergic inhibition was elevated after pentylone and MDMA self-administration: pentylone increased both GABA release and postsynaptic receptor function, while MDMA increased only postsynaptic function. Both drugs disrupted kappa opioid receptor signaling, with both agonist and antagonist decreasing GABA release, indicating non-canonical pathways. These findings suggest central amygdala GABA and kappa opioid mechanisms are critically involved in entactogen self-administration escalation.
Frontiers in Behavioral Neuroscience
December 3, 2021
Michael Colla, Hanne Scheerer, Steffi Weidt et al.
9 citations
Ketamine's rapid antidepressant effects challenge traditional theories that focus on monoaminergic pathways. Current research explores mechanisms including glutamatergic disinhibition, neurotrophic, and neuroplastic effects. Despite extensive study, ketamine has not yet led to new therapies beyond itself, and significant knowledge gaps and study limitations remain.
Frontiers in Behavioral Neuroscience
August 2, 2018
Barbara Budzynska, Artur Wnorowski, Katarzyna Kaszubska et al.
9 citations
MDMA (ecstasy) and nicotine activate shared neuronal pathways. In male Swiss mice, a single injection of MDMA (1 mg/kg) or MDMA combined with nicotine (0.05 mg/kg) improved memory consolidation in a passive avoidance test. MDMA also increased locomotor activity in mice that had developed behavioral sensitization to nicotine. The study reports for the first time strong behavioral and biochemical interactions between the two drugs, including effects on oxidative stress and α7 nicotinic acetylcholine receptor expression in the prefrontal cortex and hippocampus. These findings may help explain why people often co-use MDMA and nicotine.
Frontiers in Behavioral Neuroscience
June 11, 2021
Maria Bernardete Cordeiro de Sousa, Maria Lara Porpino de Meiroz Grilo, Nicole Leite Galvão‐coelho
7 citations
Marmosets, studied in their natural habitat using non-invasive fecal hormone measurements, are mainly monogamous, live in stable social groups with female competition and male cooperation, and form social bonds similar to humans, making them a potential model for social stress disorders. Laboratory studies confirm these behaviors and show sexually dimorphic responses to challenges influenced by age and social context. Their good adaptation to captivity, twin births, small size, and life cycle advantages have led to their use as animal models for psychiatric diseases like major depression. Juvenile marmosets have been used to develop a depression model and test Ayahuasca as an alternative treatment, with positive results encouraging further studies.
Frontiers in Behavioral Neuroscience
June 10, 2026
Swapan Samanta, Nirmal Sultania, Mukul Roychoudhury et al.
A theoretical model proposes that kundalini, described in yogic literature as a transformative psychophysiological process, may correspond to measurable neurophysiological states of autonomic integration. Preliminary retrospective clinical observations from 404 patients treated for autonomic dysregulation, sleep disturbance, and attentional dysfunction showed patterns of improved heart rate variability, cortisol rhythm restoration, and attentional stability. These patterns followed a four-stage sequence tracked by a proposed neural dispersion index: fragmentation, dormant baseline, progressive integration, and threshold coherence. The model generates four falsifiable predictions but requires formal prospective investigation before clinical conclusions can be drawn.