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Jiao S, Li N, Cao T, Wang L, Chen H, Lin C, Cai H. Differential impact of intermittent versus continuous treatment with clozapine on fatty acid metabolism in the brain of an MK-801-induced mouse model of schizophrenia. Prog Neuropsychopharmacol Biol Psychiatry 2024; 133:111011. [PMID: 38642730 DOI: 10.1016/j.pnpbp.2024.111011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 03/30/2024] [Accepted: 04/14/2024] [Indexed: 04/22/2024]
Abstract
Continuous antipsychotic treatment is often recommended to prevent relapse in schizophrenia. However, the efficacy of antipsychotic treatment appears to diminish in patients with relapsed schizophrenia and the underlying mechanisms are still unknown. Moreover, though the findings are inconclusive, several recent studies suggest that intermittent versus continuous treatment may not significantly differ in recurrence risk and therapeutic efficacy but potentially reduce the drug dose and side effects. Notably, disturbances in fatty acid (FA) metabolism are linked to the onset/relapse of schizophrenia, and patients with multi-episode schizophrenia have been reported to have reduced FA biosynthesis. We thus utilized an MK-801-induced animal model of schizophrenia to evaluate whether two treatment strategies of clozapine would affect drug response and FA metabolism differently in the brain. Schizophrenia-related behaviors were assessed through open field test (OFT) and prepulse inhibition (PPI) test, and FA profiles of prefrontal cortex (PFC) and hippocampus were analyzed by gas chromatography-mass spectrometry. Additionally, we measured gene expression levels of enzymes involved in FA synthesis. Both intermittent and continuous clozapine treatment reversed hypermotion and deficits in PPI in mice. Continuous treatment decreased total polyunsaturated fatty acids (PUFAs), saturated fatty acids (SFAs) and FAs in the PFC, whereas the intermittent administration increased n-6 PUFAs, SFAs and FAs compared to continuous administration. Meanwhile, continuous treatment reduced the expression of Fads1 and Elovl2, while intermittent treatment significantly upregulated them. This study discloses the novel findings that there was no significant difference in clozapine efficacy between continuous and intermittent administration, but intermittent treatment showed certain protective effects on phospholipid metabolism in the PFC.
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Affiliation(s)
- Shimeng Jiao
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China; Institute of Clinical Pharmacy, Central South University, Changsha, China; International Research Center for Precision Medicine, Transformative Technology and Software Services, Hunan, China
| | - Nana Li
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China; Institute of Clinical Pharmacy, Central South University, Changsha, China; International Research Center for Precision Medicine, Transformative Technology and Software Services, Hunan, China
| | - Ting Cao
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China; Institute of Clinical Pharmacy, Central South University, Changsha, China; International Research Center for Precision Medicine, Transformative Technology and Software Services, Hunan, China
| | - Liwei Wang
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China; Institute of Clinical Pharmacy, Central South University, Changsha, China; International Research Center for Precision Medicine, Transformative Technology and Software Services, Hunan, China
| | - Hui Chen
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China; Institute of Clinical Pharmacy, Central South University, Changsha, China; International Research Center for Precision Medicine, Transformative Technology and Software Services, Hunan, China
| | - Chenquan Lin
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China; Institute of Clinical Pharmacy, Central South University, Changsha, China; International Research Center for Precision Medicine, Transformative Technology and Software Services, Hunan, China
| | - Hualin Cai
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China; Institute of Clinical Pharmacy, Central South University, Changsha, China; International Research Center for Precision Medicine, Transformative Technology and Software Services, Hunan, China; National Clinical Research Center on Mental Disorders, Changsha, China.
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Tranter MM, Faget L, Hnasko TS, Powell SB, Dillon DG, Barnes SA. Postnatal Phencyclidine-Induced Deficits in Decision Making Are Ameliorated by Optogenetic Inhibition of Ventromedial Orbitofrontal Cortical Glutamate Neurons. BIOLOGICAL PSYCHIATRY GLOBAL OPEN SCIENCE 2024; 4:264-274. [PMID: 38298783 PMCID: PMC10829674 DOI: 10.1016/j.bpsgos.2023.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/12/2023] [Accepted: 08/01/2023] [Indexed: 02/02/2024] Open
Abstract
Background The orbitofrontal cortex (OFC) is essential for decision making, and functional disruptions within the OFC are evident in schizophrenia. Postnatal phencyclidine (PCP) administration in rats is a neurodevelopmental manipulation that induces schizophrenia-relevant cognitive impairments. We aimed to determine whether manipulating OFC glutamate cell activity could ameliorate postnatal PCP-induced deficits in decision making. Methods Male and female Wistar rats (n = 110) were administered saline or PCP on postnatal days 7, 9, and 11. In adulthood, we expressed YFP (yellow fluorescent protein) (control), ChR2 (channelrhodopsin-2) (activation), or eNpHR 3.0 (enhanced halorhodopsin) (inhibition) in glutamate neurons within the ventromedial OFC (vmOFC). Rats were tested on the probabilistic reversal learning task once daily for 20 days while we manipulated the activity of vmOFC glutamate cells. Behavioral performance was analyzed using a Q-learning computational model of reinforcement learning. Results Compared with saline-treated rats expressing YFP, PCP-treated rats expressing YFP completed fewer reversals, made fewer win-stay responses, and had lower learning rates. We induced similar performance impairments in saline-treated rats by activating vmOFC glutamate cells (ChR2). Strikingly, PCP-induced performance deficits were ameliorated when the activity of vmOFC glutamate cells was inhibited (halorhodopsin). Conclusions Postnatal PCP-induced deficits in decision making are associated with hyperactivity of vmOFC glutamate cells. Thus, normalizing vmOFC activity may represent a potential therapeutic target for decision-making deficits in patients with schizophrenia.
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Affiliation(s)
- Michael M. Tranter
- Department of Psychiatry, University of California San Diego, La Jolla, California
- Research Service, VA San Diego Healthcare System, La Jolla, California
| | - Lauren Faget
- Department of Neurosciences, University of California San Diego, La Jolla, California
| | - Thomas S. Hnasko
- Research Service, VA San Diego Healthcare System, La Jolla, California
- Department of Neurosciences, University of California San Diego, La Jolla, California
| | - Susan B. Powell
- Department of Psychiatry, University of California San Diego, La Jolla, California
- Research Service, VA San Diego Healthcare System, La Jolla, California
| | - Daniel G. Dillon
- Center for Depression, Anxiety and Stress Research, McLean Hospital, Belmont, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - Samuel A. Barnes
- Department of Psychiatry, University of California San Diego, La Jolla, California
- Research Service, VA San Diego Healthcare System, La Jolla, California
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Janus A, Lustyk K, Pytka K. MK-801 and cognitive functions: Investigating the behavioral effects of a non-competitive NMDA receptor antagonist. Psychopharmacology (Berl) 2023; 240:2435-2457. [PMID: 37725119 PMCID: PMC10640442 DOI: 10.1007/s00213-023-06454-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 08/21/2023] [Indexed: 09/21/2023]
Abstract
RATIONALE MK-801 (dizocilpine) is a non-competitive NMDA receptor antagonist originally explored for anticonvulsant potential. Despite its original purpose, its amnestic properties led to the development of pivotal models of various cognitive impairments widely employed in research and greatly impacting scientific progress. MK-801 offers several advantages; however, it also presents drawbacks, including inducing dose-dependent hyperlocomotion or ambiguous effects on anxiety, which can impact the interpretation of behavioral research results. OBJECTIVES The present review attempts to summarize and discuss the effects of MK-801 on different types of memory and cognitive functions in animal studies. RESULTS A plethora of behavioral research suggests that MK-801 can detrimentally impact cognitive functions. The specific effect of this compound is influenced by variables including developmental stage, gender, species, strain, and, crucially, the administered dose. Notably, when considering the undesirable effects of MK-801, doses up to 0.1 mg/kg were found not to induce stereotypy or hyperlocomotion. CONCLUSION Dizocilpine continues to be of significant importance in preclinical research, facilitating the exploration of various procognitive therapeutic agents. However, given its potential undesirable effects, it is imperative to meticulously determine the appropriate dosages and conduct supplementary evaluations for any undesirable outcomes, which could complicate the interpretation of the findings.
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Affiliation(s)
- Anna Janus
- Department of Pharmacodynamics, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688, Krakow, Poland
| | - Klaudia Lustyk
- Department of Pharmacodynamics, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688, Krakow, Poland
| | - Karolina Pytka
- Department of Pharmacodynamics, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688, Krakow, Poland.
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