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
January 3, 2014
Marie Vandekerckhove, Luis Carlo Bulnes, Jaak Panksepp
65 citations
Consciousness arises from a foundational, primitive form called anoetic consciousness—a basic, first-person flow of affective, homeostatic, and sensory-perceptual experiences. This rudimentary state underlies all learning and memory, giving rise to noetic (knowledge-based) consciousness and, eventually, autonoetic consciousness, which enables mental time travel—reflecting on past experiences and imagining future possibilities. The authors propose a multi-tiered neuroevolutionary framework linking genetically controlled primary processes (affective), secondary processes (learning and memory), and higher tertiary processes (developmentally emergent), explaining how affective experiences become cognitive and object-oriented, leading to episodic memory and self-aware awareness.
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
March 21, 2023
Shiao-Fei Guu, Yi-Ping Chao, Feng-Ying Huang et al.
28 citations
Two distinct mindfulness practices—breathing and body scan—produce different patterns of brain connectivity after an 8-week mindfulness-based stress reduction (MBSR) program. Using fMRI, the study examined the salience network (SN) in 18 meditation-naïve participants who completed MBSR and 14 waitlist controls. Breathing (fixed attention) increased long-distance SN connectivity to occipital regions, while body scan (shifting attention) increased SN connectivity to frontal and central gyri and boosted local neural coherence in the parietal lobe. During mindfulness practices after MBSR, distant and local connections became positively correlated, suggesting globally enhanced SN information processing. The small sample limits generalizability.
Frontiers in Behavioral Neuroscience
February 10, 2022
Matthew B. Pomrenze, Franciely Paliarin, Rajani Maiya
27 citations
Substance use disorders are shaped by social experiences: positive social interactions are naturally rewarding, while aggression from others can increase sensitivity to drugs, promote drug-taking, and trigger relapse. Withdrawal and prolonged abstinence lead to social avoidance and reduced social motivation, which intensify cravings and facilitate relapse. The authors discuss overlapping brain circuits and neurochemicals that underlie both social and addictive behaviors, and they highlight recent findings on MDMA that suggest a functional separation and convergence of social and reward circuits. They argue that understanding these interactions could inform treatments that break addiction cycles by leveraging the competitive nature of social versus drug rewards.
Frontiers in Behavioral Neuroscience
July 23, 2021
Hadley Rahrig, James M. Bjork, Camila Tirado et al.
17 citations
Reactive aggression, a hostile response to perceived threat, has been linked to emotion regulation failures. A pilot study compared two weeks of mindfulness training (MT) to active coping training (CT) in healthy adults, using fMRI during a retaliatory aggression task. The groups did not differ in aggression levels. However, MT participants showed greater ventromedial prefrontal cortex (vmPFC) activity during punishment events, while CT participants showed greater dorsomedial prefrontal cortex (dmPFC) activity when deciding retaliation. The findings suggest mindfulness and cognitive control training may regulate aggression through different neural circuits at different stages of provocation.
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
January 1, 2022
Maria Lara Porpino de Meiroz Grilo, Geovan Menezes de Sousa, Lilían Andrade Carlos de Mendonça et al.
12 citations
Repeated ayahuasca administration before and during social isolation prevented depressive-like behaviors and cortisol alterations in common marmosets. Animals given ayahuasca showed higher cortisol reactivity and fecal cortisol levels similar to family-group controls, no signs of anhedonia, and no increase in chronic stress-related behaviors, unlike isolated animals that received no intervention. The findings suggest ayahuasca promotes resilient responses and may have a prophylactic action against depression.
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 23, 2024
Aldrich Chan, Philip D. Harvey, R Hernandez-Cardenache et al.
9 citations
Traumatic responses outside a PTSD diagnosis are linked to changes in default mode network (DMN) functioning. In a study of 27 participants (16 trauma-exposed, 11 non-trauma-exposed), with 15 completing neuroimaging, the trauma-exposed group showed reduced self-referential processing, social cognition, autobiographical recall, and prospection, alongside increased mind-wandering. Correlations between cognitive findings and brain volume were observed, but volumetric differences between groups were insignificant. This suggests that preserved DMN structural integrity may support resilience, and that reduced hippocampal volume may be a pre-existing vulnerability to PTSD rather than a consequence, with DMN-related cognitive reductions being functionally mediated.
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.
Frontiers in Behavioral Neuroscience
January 1, 2026
Dayna Forsyth, Nicoletta Faraone, Simon G. Lamarre et al.
Psilocybin reduces aggression and activity in mangrove rivulus fish, an emerging model for studying psychoactive compounds. Waterborne psilocybin treatment significantly decreased activity levels and the frequency of swimming bursts, an aggressive behavior, toward a conspecific fish from a different lineage, with modest effects on other behaviors. Considerable intraspecific variation in behavioral response occurred among these homozygous fish, suggesting the effects were largely independent of genotype. The findings add to evidence supporting psilocybin's potential as a therapeutic agent.
Frontiers in Behavioral Neuroscience
July 1, 2025
Richard G. Hunter, Annelise Madison, Jonathon K. Lisano et al.
In people with anxiety, baseline inflammatory status moderates how cannabis use affects negative affect and sleep quality. Over four weeks, participants with mild or greater anxiety who used cannabis chemovars higher in cannabidiol (CBD) showed more consistent improvements in mood and sleep, whereas improvements with delta-9-tetrahydrocannabinol (THC)-dominant chemovars varied depending on the individual's baseline inflammation. No group-dependent changes in cytokine concentrations were observed over the study period.
Frontiers in Behavioral Neuroscience
January 1, 2025
Kelly Barnett, Fabian Vasiu
Flow, the state of complete immersion in a task, involves dynamic interactions between the default mode network (DMN) and the executive control network (ECN) in the brain. A review of nine neuroimaging studies found that flow is consistently associated with reduced activity in DMN regions linked to self-referential thought and increased activity in ECN areas supporting attentional control. Functional connectivity between these typically anti-correlated networks may enable simultaneous idea generation and goal-directed processing, supporting creativity. Reduced amygdala activity and insula-reward network coupling during flow suggest potential benefits for emotional regulation, allowing high focus with low anxiety. The findings indicate flow is a unique neurocognitive phenomenon marked by selective DMN suppression and enhanced ECN engagement.
Frontiers in Behavioral Neuroscience
April 14, 2022
Shuai Yang, Ke Xu, Xuan Xu et al.
A single injection of S-ketamine (5 mg/kg) reduced mechanical pain sensitivity and anxiety-like behaviors in adult male rats that had been exposed to a single-prolonged stress model of post-traumatic stress disorder. The treatment also lowered pro-inflammatory cytokines (TNF-α, IL-1β) and microglia activation in the dorsal striatum and periaqueductal gray, but not in the anterior cingulate cortex or prefrontal cortex. Phosphorylated NF-κB was elevated in the dorsal striatum and reduced by S-ketamine. The results suggest S-ketamine may alleviate pain and anxiety in PTSD by dampening inflammation in specific brain regions.
Frontiers in Behavioral Neuroscience
March 2, 2022
Yaping Chen, Mengxin Shen, Xu Liu et al.
Blocking glutamate transporter 1 (GLT1) with dihydrokainic acid (DHK) prevents ketamine's antidepressant-like effects in mice and reduces phosphorylation of mTOR in the prefrontal cortex. Inhibiting AMPA receptors or L-type voltage-dependent calcium channels (L-VDCC) also abolishes ketamine's antidepressant-like effect. L-VDCC inhibition blocks ketamine-induced upregulation of GLT1 and BDNF, while AMPA receptor inhibition only reduces BDNF. GLT1 appears to be a critical presynaptic molecule in depression's pathophysiology and ketamine's mechanism, with AMPA receptors and L-VDCC both essential for the immediate antidepressant-like effect.
Frontiers in Behavioral Neuroscience
January 1, 2021
Brian Key, Oressia Zalucki, Deborah J Brown
Subjective experience of sensory stimuli depends on the brain's awareness of its own internal neural processing, which in turn relies on predictions from hierarchically organized forward models of internal sensory processing. This specialized neural architecture is required for conscious awareness; without it, a nervous system cannot subjectively experience stimuli. Using nociception as a model, the authors show that the Drosophila brain lacks the internal neural connectivity needed for hierarchical forward models. They conclude that Drosophila and insects with similar neuroanatomy do not subjectively experience noxious stimuli and therefore cannot feel pain.
Frontiers in Behavioral Neuroscience
January 1, 2020
Thurston Lacalli
The evolution of consciousness from a pre-conscious state presents conceptual difficulties analogous to biological pattern formation, as described by Alan Turing. Just as molecular-level statistical variations can seed biological patterns, the microstructure of synaptic networks and their activity patterns can vary, with some variants serving as neural correlates of consciousness (NCCs). If NCCs must be precisely ordered to evoke specific experiences, Turing's framework helps explain how such order arises developmentally and how neural changes correlate with conscious experience. The analysis does not address the ultimate nature of consciousness but shows that once sentience emerges, evolution can elaborate and shape that experience.