Related Experiment Video
Updated: Oct 19, 2025
Assessment of Memory Function in Pilocarpine-induced Epileptic Mice
Published on: June 4, 2020
Recurrent febrile seizures alter intrahippocampal temporal coordination but do not cause spatial learning impairments
Michelle L Kloc1, Jennifer M Daglian2, Gregory L Holmes1
1Department of Neurological Sciences, Epilepsy Development and Cognition Group, Larner College of Medicine, University of Vermont, Burlington, Vermont, USA.
Insights
Recurrent febrile seizures (RFSs) in early life do not impair spatial learning in rats. However, these seizures alter hippocampal activity, indicating long-term changes in brain temporal organization.
Area of Science:
- Neuroscience
- Pediatric Neurology
- Epilepsy Research
Background:
- Febrile seizures (FSs) are common in children, with prolonged seizures (febrile status epilepticus) potentially causing neurological issues.
- Brief recurrent febrile seizures (RFSs) represent an intermediate condition with limited research on their long-term effects.
- Understanding RFSs is crucial for assessing potential cognitive and neurological impacts in children.
Purpose of the Study:
- To investigate the impact of early-life recurrent febrile seizures (RFSs) on spatial learning and memory.
- To analyze spontaneous hippocampal CA1 circuit activity following experimental RFSs (eRFSs).
- To determine if altered hippocampal signaling dynamics correlate with behavioral deficits.
Main Methods:
- Adult rats with a history of early-life eRFSs were assessed using a hippocampus-dependent active avoidance task.
- High-density laminar probes were used to record spontaneous hippocampal CA1 activity in anesthetized rats.
- Recordings captured activity from CA1 input regions, including CA3 and the entorhinal cortex.
Main Results:
- Rats with a history of eRFSs showed no deficits in spatial learning and memory on the active avoidance task.
- In vivo recordings revealed significantly altered theta and gamma bandwidth power and frequency in eRFS rats.
- Altered CA1 neuronal input/output dynamics were observed, but did not impair spatial behavior.
Conclusions:
- Early-life recurrent febrile seizures (eRFSs) do not lead to spatial cognitive impairments in the active avoidance task.
- Despite intact behavior, eRFSs induce lasting changes in the temporal organization of the hippocampus.
- These findings highlight subtle but significant long-term neurological alterations following recurrent febrile seizures.
Objective:
Febrile seizures (FSs) are the most common form of seizures in children. Single short FSs are benign, but FSs lasting longer than 30 min, termed febrile status epilepticus, may result in neurological sequelae. However, there is little information about an intermediary condition, brief recurrent FSs (RFSs). The goal of this study was to determine the role of RFSs on spatial learning and memory and the properties of spontaneous hippocampal signals.
Methods:
A hippocampus-dependent active avoidance task was used to assess spatial learning and memory in adult rats that underwent experimental RFSs (eRFSs) in early life compared with their littermate controls. Following completion of the task, we utilized high-density laminar probes to measure spontaneous hippocampal CA1 circuit activity under urethane anesthesia, which allowed for the simultaneous recording of input regions in CA1 associated with both CA3 and entorhinal cortex.
Results:
RFSs did not result in deficits in the active avoidance spatial test, a hippocampus-dependent test of spatial learning and memory. However, in vivo high-density laminar electrode recordings from eRFS rats had significantly altered power and frequency expression of theta and gamma bandwidths as well as signaling efficacy along the CA1 somatodendritic axis. Thus, although eRFS modified CA1 neuronal input/output dynamics, these alterations were not sufficient to impair active avoidance spatial behavior.
Significance:
These findings indicate that although eRFSs do not result in spatial cognitive deficits in the active avoidance task, recurrent seizures do alter the brain and result in longstanding changes in the temporal organization of the hippocampus.
More Related Videos
19:57The Use of Trace Eyeblink Classical Conditioning to Assess Hippocampal Dysfunction in a Rat Model of Fetal Alcohol Spectrum Disorders
Published on: August 5, 2017
10:59Investigations on Alterations of Hippocampal Circuit Function Following Mild Traumatic Brain Injury
Published on: November 19, 2012
Related Concept Videos
01:19Role of Hippocampus in Memory
01:24Epilepsy and Seizures: Overview
Various factors can trigger epilepsy, including genetic factors, brain damage, metabolic causes, and unknown etiology. Diagnosis of epilepsy involves electroencephalography (EEG), which...
01:13Seizures: Classification
Seizures are typically classified into two main categories: focal and generalized seizures.
Focal Seizures
Focal seizures originate from specific regions of the brain. These seizures are further sub-classified into two types: