Immediate and delayed treatment with gabapentin, carbamazepine and CNQX have almost similar impact on cognitive functions and behavior in the lithium-pilocarpine model in rats

Cognitive comorbidities in the rat pilocarpine model of epilepsy

Patients with epilepsy are prone to cognitive decline, depression, anxiety and other behavioral disorders. Cognitive comorbidities are particularly common and well-characterized in people with temporal lobe epilepsy, while inconsistently addressed in epileptic animals. Therefore, the aim of this study was to ascertain whether there is good evidence of cognitive comorbidities in animal models of epilepsy, in particular in the rat pilocarpine model of temporal lobe epilepsy. We searched the literature published between 1990 and 2023. The association of spontaneous recurrent seizures induced by pilocarpine with cognitive alterations has been evaluated by using various tests: contextual fear conditioning (CFC), novel object recognition (NOR), radial and T-maze, Morris water maze (MWM) and their variants. Combination of results was difficult because of differences in methodological standards, in number of animals employed, and in outcome measures. Taken together, however, the analysis confirmed that pilocarpine-induced epilepsy has an effect on cognition in rats, and supports the notion that this is a valid model for assessment of cognitive temporal lobe epilepsy comorbidities in preclinical research.

AMPA receptor neurotransmission and therapeutic applications: A comprehensive review of their multifaceted modulation

The neuropharmacological community has shown a strong interest in AMPA receptors as critical components of excitatory synaptic transmission during the last fifteen years. AMPA receptors, members of the ionotropic glutamate receptor family, allow rapid excitatory neurotransmission in the brain. AMPA receptors, which are permeable to sodium and potassium ions, manage the bulk of the brain's rapid synaptic communications. This study thoroughly examines the recent developments in AMPA receptor regulation, focusing on a shift from single chemical illustrations to a more extensive investigation of underlying processes. The complex interplay of these modulators in modifying the function and structure of AMPA receptors is the main focus, providing insight into their influence on the speed of excitatory neurotransmission. This research emphasizes the potential of AMPA receptor modulation as a therapy for various neurological disorders such as epilepsy and Alzheimer's disease. Analyzing these regulators' sophisticated molecular details enhances our comprehension of neuropharmacology, representing a significant advancement in using AMPA receptors for treating intricate neurological conditions.

The effect of gabapentin and pregabalin administration on memory in clinical and preclinical studies: a meta-analysis and systematic review

BACKGROUND

Today, gabapentinoids such as Gabapentin (GBP) and pregabalin (PGB) are widely used as painkillers. This may alter the function of the nervous system; hence their results may include a difference in memory and processes that end in memory formation. This study aims to conclude whether gabapentinoids can alter memory or not by reviewing and analyzing clinical and preclinical studies.

MATERIAL AND METHODS

A comprehensive search was carried out in databases including PUBMED, EMBASE, SCOPUS, and Web of Science. In the included studies, memory was measured as an outcome variable in clinical or preclinical studies.

RESULT

A total of 21 articles (4 clinical, 17 preclinical) were included in the meta-analysis by STATA Software. The results showed that memory changes under the influence of GBP. Both the administrated dosage and the time of administration are important in the final results and latency time of retention. GBP administration in healthy animals increased latency time, whereas if the administration of GBP took place exactly before training, the latency time increased slightly. Short-term administration of PGB in healthy volunteers is accompanied by transient side effects on the CNS. However, the number and homogeneity of the studies were not such that a meta-analysis could be performed on them.

CONCLUSION

Clinical and preclinical studies showed that PGB administration did not confirm its improving memory effect. GBP administration in healthy animals increased latency time and improved memory. Although it depended on the time of administration.

Mirogabalin, a novel ligand for α2δ subunit of voltage-gated calcium channels, improves cognitive impairments in repeated intramuscular acidic saline injection model rats, an experimental model of fibromyalgia

Mirogabalin is a novel potent and selective ligand for the α₂δ subunit of voltage-gated calcium channels, and shows potent and sustained analgesic effects in neuropathic pain and fibromyalgia models. Fibromyalgia is often associated with multiple comorbid symptoms, such as anxiety, depression and cognitive impairment. In the present study, we investigated the effects of mirogabalin on cognitive impairments in an experimental animal model for fibromyalgia, repeated intramuscular acidic saline injection model (Sluka model) rats. Male rats received two repeated intramuscular injections of pH 4 acidic saline into their gastrocnemius muscle. After developing mechanical hypersensitivity as identified in the von Frey test, the animals received the test substance orally once daily for 13 days and were subjected to four cognitive function tests, (Y-maze, novel object recognition, Morris water maze and step-through passive avoidance). Sluka model rats showed cognitive impairments in all four tests. Oral administration of mirogabalin (3 and 10 mg/kg) improved the cognitive impairments in these rats. In conclusion, mirogabalin improved the impaired cognitive function in Sluka model rats. It may thus also alleviate cognitive impairments as well as painful symptoms in fibromyalgia patients.

Depression and Anxiety in the Epilepsies: from Bench to Bedside

PURPOSE OF REVIEW

Depression and anxiety substantially contribute to interictal disability in patients with epilepsy (PWE). This review summarizes current studies that shed light on mechanisms of comorbidity.

RECENT FINDINGS

Mounting epidemiological data implicate shared risk factors for anxiety/depression and seizure propensity, but these remain largely elusive and probably vary by epilepsy type. Within PWE, these symptoms appear to be associated with unique genetic, neuropathological, and connectivity profiles. Temporal lobe epilepsy has received enormous emphasis particularly in preclinical studies of comorbidity, where candidate neurobiological mechanisms underlying bidirectionality have been tested without psychopharmacological confounds. Depression and anxiety in epilepsy reflect dysfunction within broadly distributed limbic networks that may be the cause or consequence of epileptogenesis. In refractory epilepsy, seizures and/or certain anticonvulsants may distort central emotional homeostatic mechanisms that perpetually raise seizure risk. Developing future safe and effective combined anticonvulsant-antidepressant treatments will require a detailed understanding of anatomical and molecular nodes that pleiotropically enhance seizure risk and negatively alter emotionality.

Interventions and cognitive functioning in adults with traumatic spinal cord injuries: a systematic review and meta-analysis

AIM

This research synthesized scientific evidence on the impact of interventions for adults with traumatic spinal cord injury on cognition, to understand if current intervention approaches are appropriate in light of the risk of post-injury cognitive impairments.

METHOD

Medline, Central, Embase, Scopus, PsycINFO and PubMed were searched for intervention in persons with SCI assessing cognition pre- and post-intervention. Study quality was completed using the National Institutes of Health quality assessment tools. Results were grouped by type of intervention. The meta-analysis involved calculation of pooled effect sizes for interventions utilizing the same cognitive measure.

RESULTS

Eleven studies of moderate quality discussed drug therapy, transcutaneous tibial nerve stimulation, diet modification and dietary supplements, and inpatient rehabilitation. Some aspects of cognition were negatively affected by drugs while diet modification and supplement use, and transcutaneous tibial nerve stimulation showed no evidence of a difference in cognitive scores when compared with no intervention. Inpatient rehabilitation revealed a small but beneficial effect, when results of seven studies were pooled.

CONCLUSION

Evidence on the effects of interventions on cognitive functioning in patients with traumatic spinal cord injury is sparse and inconclusive, so work in this area is timely. It is valuable to know not only which interventions are effective for improving cognition, but also how other commonly used interventions, intended to treat other injury sequela, can affect cognition. PROSPERO: CRD42018087238.Implications for rehabilitationHistorically, rehabilitation of patients with traumatic spinal cord injury has targeted physical impairments, with little attention to cognition; this research aimed to understand if current interventions are appropriate in light of the risk of patients' cognitive impairments. Evidence on the effects of drug therapy, diet and dietary supplements interventions on cognitive functioning in traumatic spinal cord injury is sparse and inconclusive.Combining multiple inpatient rehabilitation interventions shows a positive but heterogeneous effect on the cognitive functioning; interventions applied earlier show greater gains.A major challenge for clinicians is to select an outcome measure sensitive to change over time, and to relate the results to patients' change in cognitive abilities with intervention applicationResearch to understand the functional effect of spinal cord injury on the widely distributed networks of the central and autonomic nervous systems subserving cognition, is timely.