Previous studies have indicated that blockade of N-methyl-D-aspartate (NMDA) subtype of glutamate receptors prevents acquisition of instrumental behaviors reinforced by food and drugs such as morphine and cocaine. The present study aimed to extend this evidence by testing whether NMDA receptor channel blocker, memantine, would exert similar effects on acquisition of cocaine and nicotine self-administration in mice. Inasmuch as memantine also acts as nicotinic receptor channel blocker, this study assessed the effects of mecamylamine and MRZ 2/621 that are more selective nicotinic blockers. Adult male Swiss mice were allowed to self-administer cocaine (0.8-2.4 microg/infusion) or nicotine (0.08-0.32 microg/infusion) during the 30-min test. Pretreatment with memantine (0.1-10 mg/kg) prevented acquisition of nicotine but not cocaine self-administration. Pretreatment with mecamylamine (0.3-3 mg/kg) and MRZ 2/621 (0.3-10 mg/kg) produced dose-dependent suppression of both cocaine and nicotine self-administration. Taken together with the previous reports, these results indicate that nicotinic receptor blockers antagonize acute reinforcing effects of cocaine while NMDA receptor blockade may have limited effectiveness.
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http://dx.doi.org/10.1016/j.euroneuro.2004.07.005 | DOI Listing |
Neuropharmacology
December 2024
Department of Experimental Physiology and Pathophysiology, Medical University of Białystok, ul. Mickiewicza 2A, 15-222 Białystok, Poland.
Although angiotensin 1-7 (Ang 1-7) and its role as a part of the "protective" axis of the renin-angiotensin system are well described in the literature, the mechanisms of its angiotensin II-like pressor and tachycardic effects following its acute central administration are not fully understood. It was the aim of the present study to examine which receptors contribute to the aforementioned cardiovascular effects. Ang 1-7 and antagonists for glutamate, GABA, vasopressin, thromboxane A (TP), α-adrenergic, and P2X purinoceptors or modulators of oxidative stress were injected into the paraventricular nucleus of the hypothalamus (PVN) of urethane-anesthetized male Wistar rats.
View Article and Find Full Text PDFJ Biol Chem
December 2024
Department of Pharmacology, Addiction Science, and Toxicology, College of Medicine, The University of Tennessee Health Science Center; Memphis, 38163. Electronic address:
Familial Alzheimer's disease (FAD) is frequently associated with mutations in the amyloid precursor protein (APP), which are thought to lead to cognitive deficits by impairing NMDA receptor (NMDAR)-dependent forms of synaptic plasticity. Given the reliance of synaptic plasticity on NMDAR-mediated Ca entry, shaping of NMDAR activity by APP and/or its disease-causing variants could provide a basis for understanding synaptic plasticity impairments associated with FAD. A region of APP (residues 639-644 within APP695) processed by the γ-secretase complex, which generates amyloid β (Aβ) peptides, is a hotspot for FAD mutations.
View Article and Find Full Text PDFArch Pharm (Weinheim)
January 2025
Department of Pharmacognosy, University Institute of Pharma Sciences, Chandigarh University, Mohali, Punjab, India.
Alzheimer's disease (AD) is a prevalent neurological illness that affects over 80% of aged adults globally in cases of dementia. Although the exact pathophysiological causes of AD remain unclear, its pathogenesis is primarily driven by several distinct biochemical alterations: (i) the accumulation of toxic Aβ plaques, (ii) the hyperphosphorylation of tau proteins, (iii) oxidative stress resulting in cell death, and (iv) an imbalance between the two main neurotransmitters, glutamate and acetylcholine (ACh). Currently, there are very few medications available and no treatment.
View Article and Find Full Text PDFJ Neurosci
December 2024
Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
Excitatory synapses and the actin-rich dendritic spines on which they reside are indispensable for information processing and storage in the brain. In the adult hippocampus, excitatory synapses must balance plasticity and stability to support learning and memory. However, the mechanisms governing this balance remain poorly understood.
View Article and Find Full Text PDFJ Clin Psychiatry
December 2024
Department of Psychiatry, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Pharmacotherapy plays a crucial role in treating attention-deficit/ hyperactivity disorder (ADHD). However, current medications for ADHD have limitations and potential adverse effects. Glutamate, a neurotransmitter that directly and indirectly modulates dopamine neurotransmission, is considered a new therapeutic target for ADHD.
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