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Jha NA, Ayoub SM, Flesher MM, Morton K, Sikkink M, de Guglielmo G, Khokhar JY, Minassian A, Brody AL, Young JW. Acute nicotine vapor normalizes sensorimotor gating and reduces locomotor activity deficits in HIV-1 transgenic rats. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.18.599641. [PMID: 38948796 PMCID: PMC11212989 DOI: 10.1101/2024.06.18.599641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Rationale Despite improved life expectancy of people with HIV (PWH), HIV-associated neurocognitive impairment (NCI) persists, alongside deficits in sensorimotor gating and neuroinflammation. PWH exhibit high smoking rates, possibly due to neuroprotective, anti-inflammatory, and cognitive-enhancing effects of nicotine, suggesting potential self-medication. Objectives Here, we tested the effects of acute nicotine vapor exposure on translatable measures of sensorimotor gating and exploratory behavior in the HIV-1 transgenic (HIV-1Tg) rat model of HIV. Methods Male and female HIV-1Tg and F344 control rats (n=57) were exposed to acute nicotine or vehicle vapor. Sensorimotor gating was assessed using prepulse inhibition (PPI) of the acoustic startle response, and exploratory behavior was evaluated using the behavioral pattern monitor (BPM). Results Vehicle-treated HIV-1Tg rats exhibited PPI deficits at low prepulse intensities compared to F344 controls, as seen previously. No PPI deficits were observed in nicotine-treated HIV1-Tg rats, however. HIV-1Tg rats were hypoactive in the BPM relative to controls, whilst nicotine vapor increased activity and exploratory behavior across genotypes. Cotinine analyses confirmed comparable levels of the primary metabolite of nicotine across genotypes. Conclusions Previous findings of PPI deficits in HIV-1Tg rats were replicated and, importantly, attenuated by acute nicotine vapor. Evidence for similar cotinine levels suggest a nicotine-specific effect in HIV-1Tg rats. HIV-1Tg rats had reduced exploratory behavior compared to controls, attenuated by acute nicotine vapor. Therefore, acute nicotine may be beneficial for remediating sensorimotor and locomotor activity deficits in PWH. Future studies should determine the long-term effects of nicotine vapor on similar HIV/NCI-relevant behaviors.
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Affiliation(s)
- Neal A. Jha
- Department of Psychiatry, University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Samantha M. Ayoub
- Department of Psychiatry, University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - M. Melissa Flesher
- Department of Psychiatry, University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Kathleen Morton
- Department of Psychiatry, University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Megan Sikkink
- Department of Psychiatry, University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Giordano de Guglielmo
- Department of Psychiatry, University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Jibran Y. Khokhar
- Department of Anatomy and Cell Biology, University of Western Ontario 1151 Richmond Street, London, ON N61 3K7, Canada
| | - Arpi Minassian
- Department of Psychiatry, University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093, USA
- Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System 3350 La Jolla Village Drive, San Diego, CA 92161, USA
| | - Arthur L. Brody
- Department of Psychiatry, University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093, USA
- Research Service, VA San Diego Healthcare System 3350 La Jolla Village Drive, San Diego, CA 92161, USA
| | - Jared W. Young
- Department of Psychiatry, University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093, USA
- Research Service, VA San Diego Healthcare System 3350 La Jolla Village Drive, San Diego, CA 92161, USA
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Sustained Functioning Impairments and Oxidative Stress with Neurobehavioral Dysfunction Associated with Oral Nicotine Exposure in the Brain of a Murine Model of Ehrlich Ascites Carcinoma: Modifying the Antioxidant Role of Chlorella vulgaris. BIOLOGY 2022; 11:biology11020279. [PMID: 35205143 PMCID: PMC8869302 DOI: 10.3390/biology11020279] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/28/2022] [Accepted: 02/04/2022] [Indexed: 12/20/2022]
Abstract
Simple Summary Nicotine is the major psychoactive component considered to underlie tobacco’s addictive nature, and its dependence has been linked to several drawbacks on behavior and brain health. The purpose of this study was to investigate the mechanisms triggered by oral nicotine that cause brain tissue damage, as well as the supportive role of Chlorella vulgaris microalgae supplementation in Ehrlich ascites carcinoma in mice. The results revealed pronounced neurobehavioral alterations, increased mortality rate, oxidative stress, DNA damage, and augmented inflammatory response in the brain tissue alongside the microstructural alteration caused by nicotine. Chlorella vulgaris was quite successful in reducing the negative effects of nicotine. It acts as an antioxidant anti-inflammatory and restores nearly normal tissue architectures. As a result, we believe it should be supplemented to cancer patients consuming regular nicotine doses. Abstract Background: This study provides a model for studying the mechanism(s) responsible for the nervous tissue damage and misfunctioning that occurred due to oral nicotine exposure, considered a stress factor, during the presence of Ehrlich ascites carcinoma bearing in the mouse model (EAC). The mitigating role of Chlorella vulgaris (CV) against nicotine-induced brain damage was evaluated. Methods: Eighty Swiss female mice were classified into four groups, these were the control, the CV group, the nicotine group(100 µg/kg), and the combination group. Oxidant/antioxidant status, proinflammatory cytokines levels, DNA damage, quantitative microscopical lesions, and Caspase 3, Bcl-2 proteins were assessed in the current study. Levels of dopamine (DA) and gamma-aminobutyric acid (GABA) were also evaluated. Results: Nicotine was found to cause pronounced neurobehavioral alterations, increase the mortalities oxidative stress DNA damage, and augment the inflammatory response in brain tissue alongside the microstructural alteration. The administration of CV with nicotine in EAC-bearing mice rescued the detrimental effects of nicotine. Conclusions: CV aids in reducing the harmful effects of nicotine and returns the conditions caused by nicotine to near-control levels. Thus, we are in favor of giving it to cancer patients who are taking daily dosages of nicotine even by smoking cigarettes or being exposed to second-hand smoke.
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