Trends in Pharmacological Sciences
September 22, 2017
Evan J. Kyzar, Charles D. Nichols, Raul R. Gainetdinov et al.
155 citations
Psilocybin, a naturally occurring hallucinogen, significantly reduced anxiety in 60% of participants with treatment-resistant anxiety disorders after just one session. In a sample of 30 individuals, those who received psilocybin reported lasting improvements in mood and well-being. The study highlighted how psychedelics like psilocybin and lysergic acid diethylamide (LSD) influence neurotransmitter receptors, offering new avenues in biomedicine and psychology. These findings suggest that psychedelics could play a critical role in addiction treatment and mental health therapy, marking a shift in pharmacology and psychotherapy approaches.
Progress in Neuro-Psychopharmacology and Biological Psychiatry
January 10, 2012
Evan J. Kyzar, Christopher Collins, Siddharth Gaikwad et al.
122 citations
Mescaline and phencyclidine (PCP) dose-dependently increased top activity in the novel tank test, reduced immobility, and disrupted swimming patterns in zebrafish. PCP, but not mescaline, evoked circling behavior in the open field test. At the highest doses tested, mescaline markedly increased shoaling behavior, while PCP did not affect it. Whole-body cortisol levels were unchanged by 20 mg/l mescaline but elevated by 3 mg/l PCP. These findings indicate that zebrafish models are sensitive to hallucinogenic compounds, producing complex behavioral and physiological effects.
Behavioural Pharmacology
April 8, 2011
Adam Stewart, Russell Riehl, Keith Wong et al.
66 citations
Acute exposure to high doses of MDMA (40-120 mg/l) reduces bottom swimming and immobility in zebrafish and impairs intrasession habituation at doses as low as 10 mg/l, while lower doses (0.25-10 mg/l) show no behavioral effects. MDMA also increases brain c-fos expression. These findings support the use of zebrafish as a model for screening hallucinogenic compounds.
Molecular psychiatry
January 1, 2023
Evan J. Kyzar, George H. Denfield
62 citations
Psychiatric diseases alter subjective experience, yet neuroscience mostly studies objective behaviors. Phenomenology, a philosophical tradition examining lived experience, can generate hypotheses about the neurobiological basis of mental illness. Early 20th-century phenomenological psychiatrists made important contributions, but this approach faded with operationalized diagnoses. Recently, clinical-phenomenological research has re-emerged. Using examples from mania and psychosis, the authors show that phenomenological studies can produce fruitful neuroscientific proposals. They advocate integrating phenomenological methods with modern neuroscience, including cross-species research and human subjects work, to move toward a unified understanding of mental illness.
Zebrafish
March 22, 2016
Evan J. Kyzar, Allan V. Kalueff
29 citations
Interest in using hallucinogens to treat brain disorders is reviving. Early studies show classic serotonergic hallucinogens like LSD and psilocybin may help with addiction, PTSD, and anxiety, but basic pharmacological and toxicological questions remain. This paper discusses psychedelic medicine and the behavioral and toxic effects of hallucinogenic drugs in zebrafish, highlighting the fish as a model for screening both toxic and therapeutic effects of known and novel hallucinogenic compounds. Well-designed zebrafish studies could support the reemerging treatment paradigm of psychedelic medicine and open new clinical avenues for psychiatric disorders.
The FASEB Journal
April 1, 2012
Evan J. Kyzar, Christopher Collins, Jeremy Green et al.
1 citation
Mescaline and phencyclidine (PCP) alter zebrafish behavior in distinct ways, while psilocybin shows no behavioral effects at the doses tested. Mescaline (10–20 mg/L) reduces anxiety-like behavior in the novel tank test, increases shoaling, and changes movement in the open field. PCP (1–3 mg/L) decreases freezing and causes erratic swimming. Both mescaline and PCP disrupt normal exploratory behavior. Psilocybin (0.5–3 mg/L) is inactive in all behavioral tests. Psilocybin and PCP raise whole-body cortisol levels without affecting brain c-fos expression; mescaline does not alter either measure. Zebrafish models are sensitive to hallucinogenic compounds with complex behavioral and physiological effects.
October 16, 2023
George H. Denfield, Evan J. Kyzar
preprint
Subjective experience is central to mental illness but has been neglected in empirical psychopathology. The Nested States Model (NSM) offers a framework for constructing detailed phenomenological models by describing subjective experience as a system of nested states. This provides a structured scheme for operationalizing subjectivity, enabling empirical study. The NSM grounds thinking about psychopathological processes around states and their transitions, promising an approach that is close to individual experience, empirically tractable, and aligned with neuroscience research.
Open MIND
January 1, 2015
Jonathan Cachat, Chris Collins, Evan J. Kyzar et al.
Three-dimensional reconstructions of zebrafish swimming paths enable both macro- and micro-level analysis of behavior, offering a more complete picture than traditional 2D traces. Temporal 3D reconstructions plot spatial data across time to reflect activity over testing, while spatial 3D reconstructions use two cameras to depict activity within the actual arena. These reconstructions are highly sensitive to anxiolytic, anxiogenic, and hallucinogenic effects in adult zebrafish. For example, ibogaine reversed natural behaviors, a characterization impossible without 3D reconstructions. Track3D, applied for the first time in adult zebrafish, showed strong significant correlation (R>0.07) of automated endpoints with manual data, providing precise calculation of movement parameters and accurate spatiotemporal integration. These approaches permit advanced movement pattern analysis for screening psychoactive compounds.