Related Experiment Video
Updated: Nov 1, 2025
07:51
Administration of Δ9-Tetrahydrocannabinol (THC) in Adolescent and Adult Mice
Published on: August 1, 2025
412
HIV-1 Tat and morphine decrease murine inter-male social interactions and associated oxytocin levels in the
Sara R Nass1, Arianna R S Lark1, Yun K Hahn2
1Department of Pharmacology and Toxicology, Virginia Commonwealth University, Medical College of Virginia (MCV) Campus, Richmond, VA 23298-0613, USA.
Hormones and Behavior
|June 25, 2021
Summary
HIV-1 Tat and morphine impair social behavior by disrupting oxytocin levels in brain circuits. This research highlights neurobiological links between HIV-1 infection, opioid use, and social deficits.
Area of Science:
- Neuroscience
- Immunology
- Pharmacology
Background:
- Individuals with HIV-1 infection and opioid dependence often exhibit social interaction deficits.
- Sociability is regulated by the prefrontal cortico-hippocampal-amygdalar circuit, which is affected by HIV-1 trans-activator of transcription (Tat) and opioids.
- Dysregulation of hypothalamic neuropeptides, including oxytocin and corticotropin-releasing factor (CRF), is linked to social behavior changes.
Purpose of the Study:
- To investigate the combined effects of HIV-1 Tat and morphine on social interactions in male mice.
- To examine the impact of HIV-1 Tat and morphine on oxytocin and CRF levels within the prefrontal cortex (PFC) and associated brain circuitry.
- To determine the correlation between neuropeptide levels and behavioral alterations.
Main Methods:
- Male mice were exposed to HIV-1 Tat for 8 weeks.
- Morphine or saline was administered during the final 2 weeks of Tat exposure.
- Social interactions were assessed using the resident-intruder test, social interaction test, and novelty test.
- Oxytocin and CRF levels, as well as oxytocin-immunoreactive neurons, were measured in specific brain regions (PFC, amygdala, hypothalamic paraventricular nucleus).
Main Results:
- HIV-1 Tat exposure alone attenuated aggressive social interactions.
- Morphine administration decreased both aggressive and non-aggressive social interactions.
- Tat, but not morphine, reduced oxytocin levels in the PFC and amygdala.
- Both Tat and morphine decreased the percentage of oxytocin-immunoreactive neurons in the hypothalamic paraventricular nucleus (PVN).
- Regional CRF and oxytocin levels correlated with behavioral changes in social interaction and novelty tests.
Conclusions:
- Decreased oxytocin expression in the prefrontal cortico-hippocampal-amygdalar circuit is associated with social behavior deficits induced by morphine and HIV-1 Tat.
- These findings elucidate the neurobiological mechanisms underlying social impairments in HIV-1 infected and opioid-dependent individuals.
- Targeting oxytocin pathways may offer therapeutic potential for social deficits in these populations.
