Physiology & Behavior
January 28, 2015
A.j. Oliveira-Lima, Renato Antunes Dos Santos, A.w. Hollais et al.
91 citations
Ayahuasca, a hallucinogenic brew, prevents the development of ethanol-induced behavioral sensitization in mice and reverses established sensitization. A single dose (30–500 mg/kg) blocked the initiation of behavioral sensitization without affecting spontaneous movement. Higher doses (300 and 500 mg/kg) selectively reduced both acute and sensitized responses to ethanol. Eight consecutive days of ayahuasca (100 or 300 mg/kg) after sensitization was established blocked its expression upon a subsequent ethanol challenge. The results suggest ayahuasca may inhibit early addiction-related behaviors and reverse long-term drug effects when administered in the ethanol-associated environment.
Physiology & Behavior
January 1, 1987
T Archer, E Arweström, B G Minor et al.
32 citations
In rats and mice, two drugs that activate serotonin receptors (8-OH-DPAT and 5-MeODMT) reliably produced pain relief in three different tests (tail-flick, hot-plate, and shock-titration). However, when the animals were pretreated with a toxin that destroys noradrenaline neurons (DSP4) given systemically, or with 6-hydroxydopamine injected directly into the spinal cord, the pain-relieving effects of both drugs were eliminated. In the tail-flick test, 8-OH-DPAT actually caused increased pain sensitivity after spinal cord noradrenaline depletion. Biochemical measurements confirmed that the toxins severely reduced noradrenaline in the spinal cord. The findings suggest that the pain relief from these serotonin drugs depends on intact noradrenaline nerve endings in the spinal cord, pointing to a critical interaction between noradrenaline and serotonin systems in spinal pain processing.
Physiology & Behavior
August 1, 2006
María E. Reverón, Esther Y. Maier, Christine L. Duvauchelle
23 citations
Rats that voluntarily self-administered moderate doses of MDMA (approximately 2.0–7.0 mg/kg/day) over 20 daily 2-hour sessions initially showed a drop in core body temperature after each session compared to baseline and to a control group that self-administered saline. Over time, this hypothermic response diminished, and by the final sessions core temperatures had risen above baseline. Locomotor activity during MDMA sessions was initially similar to saline levels but became significantly greater by day 8. These findings demonstrate that repeated voluntary MDMA intake leads to experience-dependent changes in temperature regulation and behavior.
Physiology & Behavior
May 3, 2011
David M. Compton, Kerri L. Dietrich, Melissa C. Selinger et al.
21 citations
The recreational hallucinogen 5-MeO-DIPT (Foxy or Methoxy Foxy) impairs cognitive flexibility in rats when administered during adolescence. Rats given repeated injections of 5 or 20 mg/kg of the drug during one of two adolescent periods were later tested as adults on spatial memory and nonspatial tasks. Drug-treated rats performed as well as controls on spatial navigation to a fixed goal, but were markedly inferior when the goal moved to a new location and on a response learning task, indicating reduced ability to adapt to changing demands. The drug also reduced serotonin activity in the forebrain, similar to MDMA, suggesting it compromises serotonergic systems.
Physiology & Behavior
October 1, 2024
Jasmine Shakir, Megan Pedicini, Brianna C Bullock et al.
5 citations
A single dose of psilocybin increased body weight in both male and female mice during the days immediately after treatment, without affecting how much they ate or drank. The weight gain was accompanied by increased lean and water mass in males, with a similar trend in females. Blocking the 5-HT2A/2C receptor with ketanserin did not prevent this effect. Blood tests showed elevated creatine kinase, aspartate aminotransferase, and chloride in treated mice. These results begin to clarify how psilocybin may influence body weight and metabolism, which is important for its safe use in clinical and non-clinical settings.
Physiology & Behavior
September 1, 2025
Yiru Dong, Sebastian Goodwin-Groen, Jessie Ma et al.
4 citations
Repeated exposure to the activity-based anorexia (ABA) animal model, which mimics key features of anorexia nervosa such as starvation-induced hyperactivity and severe weight loss, can build resilience against relapse through synaptic changes. Sub-anesthetic ketamine given during mid-adolescence enhances this resilience. At medial prefrontal cortex synapses, ketamine increases GluN2B-containing NMDA receptors and the F-actin binding protein drebrin at excitatory synapses on pyramidal cells and GABA-interneurons. These molecular changes occur near 15 days post-injection during relapse in late adolescence. Ketamine treatment in late adolescence also reduces ABA relapse in adulthood, though less effectively. Wheel running promotes inhibitory GABAergic synapse formation on hippocampal pyramidal cells, and ketamine augments this inhibition, suppressing starvation-evoked hyperactivity and increasing food consumption and weight gain.
Physiology & Behavior
May 20, 2025
Kaspar McCoy, Felicia Reed, Kyna‐anne Conn et al.
4 citations
Psilocybin, a serotonergic psychedelic, shows promise for treating anorexia nervosa by enhancing cognitive flexibility and modifying reward processing—two core processes disrupted in the disorder. Its effects are primarily mediated by the 5-HT2A receptor, but recent evidence indicates broader interactions with dopaminergic pathways in brain regions like the prefrontal cortex and nucleus accumbens. Rodent models demonstrate that psilocybin induces rapid and enduring neuroplastic changes, improving cognitive flexibility through complex neurochemical mechanisms. Advances in real-time neurochemical recording now allow simultaneous monitoring of serotonin and dopamine signaling, which will provide insights into their coordinated actions during cognitive performance. Further research into psilocybin's dual modulation of these systems is needed to optimize therapeutic applications for anorexia nervosa.
Physiology & Behavior
April 17, 2026
Li Shen Chong, Rachel C. Bucher, Edward Merritt et al.
A brief mindfulness intervention (bMBI) alters the autonomic nervous system (ANS) and improves coordination between its subsystems. In young adults, two sessions of bMBI increased respiratory sinus arrhythmia (RSA) and reduced skin conductance level (SCL) during mindfulness practice compared to an audiobook-listening control group. The bMBI group also showed greater declines in blood pressure during mindfulness and after a psychosocial stress test. During stress, the bMBI group displayed reciprocal RSA-SCL patterns (RSA up, SCL down), while controls showed non-reciprocal coordination (both up). These results suggest that examining coordination across ANS measures can explain prior inconsistent findings and that brief mindfulness may promote adaptive stress responses.
Physiology & Behavior
March 15, 2015
Hwi-Jin Im, Yoon-Jung Kim, Hyeong-Geug Kim et al.
A traditional Korean mind-body practice, Kouksundo, reduces oxidative stress markers and alters stress hormones. In 57 trainees, a single session (90 minutes total) lowered blood levels of reactive oxygen species, nitric oxide, and malondialdehyde, while increasing superoxide dismutase and decreasing catalase. Cortisol, norepinephrine, and dopamine decreased, while epinephrine increased. Total antioxidant capacity and glutathione were unchanged. The practice appears to offer health benefits through these biological changes.