eISSN: 1509-572x
ISSN: 1641-4640
Folia Neuropathologica
Current issue Archive Manuscripts accepted About the journal Special Issues Editorial board Reviewers Abstracting and indexing Subscription Contact Instructions for authors Ethical standards and procedures
Editorial System
Submit your Manuscript
SCImago Journal & Country Rank
3/2019
vol. 57
 
Share:
Share:
abstract:
Original paper

Effects of topiramate on the ultrastructure of synaptic endings in the hippocampal CA1 and CA3 sectors in the rat experimental model of febrile seizures: the first electron microscopy report

Joanna Maria Łotowska
1
,
Piotr Sobaniec
2
,
Maria Elżbieta Sobaniec-Łotowska
1
,
Barbara Szukiel
2
,
Małgorzata Łukasik
1
,
Sylwia Barbara Łotowska
3

  1. Department of Medical Pathomorphology, Medical University of Bialystok, Poland
  2. Department of Paediatric Neurology and Rehabilitation, Medical University of Bialystok, Poland
  3. Department of Laboratory Diagnostics, Maria Skłodowska-Curie Memorial Bialystok Oncology Center, Bialystok, Poland
Folia Neuropathol 2019; 57 (3): 267-276
Online publish date: 2019/09/30
View full text Get citation
 
PlumX metrics:
The present study aimed at exploring a potentially neuroprotective effect of topiramate (TPM), one of the most commonly used newer-generation, broad-spectrum, antiepileptic drugs against ultrastructural damage of hippocampal synaptic endings in the experimental model of febrile seizures (FS). The study used male young Wistar rats aged 22-30 days, divided into three experimental groups and the control group. Brain maturity in such animals corresponds to that of 1- or 2-year-old children. Hyperthermic stress was evoked by placing animals in a 45°C water bath for four consecutive days. TPM at a dose of 80 mg/kg b.m. was administered with an intragastric tube before and immediately after FS. Specimens (1 mm3) collected from the hippocampal CA1 and CA3 sectors, fixed via transcardial perfusion with a solution of paraformaldehyde and glutaraldehyde, were routinely processed for transmission-electron microscopic analysis. Advanced ultrastructural changes induced by hyperthermic stress were manifested by distinct swelling of hippocampal pre- and post-synaptic axodendritic and axospinal endings, including their vacuolization and disintegration. The axoplasm of the presynaptic boutons contained a markedly decreased number of synaptic vesicles and their abnormal accumulation in the active synaptic region. The synaptic junctions showed a dilated synaptic cleft and a decreased synaptic active zone. TPM used directly after FS was ineffective in the prevention of hyperthermia-induced injury of synaptic endings in hippocampal CA1 and CA3 sectors. However, “prophylactic” administration of TPM, prior to FS induction, demonstrated a neuroprotective effect against synaptic damage in approximately 25% of the synaptic endings in the hippocampal sectors, more frequently located in perivascular zones. It was manifested by smaller oedema of both presynaptic and postsynaptic parts, containing well-preserved mitochondria, increased number and regular distribution of synaptic vesicles within the axoplasm, and increased synaptic active zone. Our current and previous findings suggest that TPM administered “prophylactically”, before FS, could exert a favourable effect on some synapses, indirectly, via the vascular factor, i.e. protecting blood-brain barrier components and through better blood supply of the hippocampal CA1 and CA3 sectors, which may have practical implications.
keywords:

ultrastructure of synaptic endings, hippocampal CA1 and CA3 sectors, experimental febrile seizures, topiramate, neuroprotection

Quick links
© 2024 Termedia Sp. z o.o.
Developed by Bentus.