DOI: 10.5281/zenodo.18577632
title: Long-term EEGs from freely behaving mice from six genotypes (wild type and TSC1 knockout across three background strains)

description: Long-term EEGs (stored in EDF format) from a genetic panel of mouse models with a tuberous sclerosis complex (TSC)-associated mutation. Specifically, a TSC1-genotype (haploinsufficiency caused by presence of TSC1 knockout) in mice from three different strains as genetic backgrounds.




All animal procedures were approved by University of Vermont IACUC and conducted in accordance with the Guide for the Humane Use and Care of Laboratory Animals. Mice were housed on a 12-hour light/dark cycle with ad libitum access to food and water, and behavioral testing was conducted during the light phase.

To generate a germline TSC1 haploinsufficient mouse, we bred a pure B6 conditional TSC1 floxed line (Strain #:038428) with a B6 mouse expressing Cre recombinase under the human CMV promoter (Strain #:006054), which drives ubiquitous expression. The resulting offspring had one TSC1 allele knocked out in all tissues and one intact. This model enables breeding with genetic reference populations to systematically investigate how genetic background influences TSC1-related phenotypes. As genetic background strains, we include BXD87/RwwJ (BXD87, Strain #:007130) and both BXD reference population parent strains: B6 (Strain #:000664) and D2 (Strain #:000671). The resulting experimental mice—BXD87B6F1-TSC1+/- (BXD87-Het), B6B6F1-TSC1+/- (C57B6-Het), D2B6F1-TSC1+/- (DBA2-Het)—were heterozygous for the TSC1 knockout and inherited half the genetic background of the reference strain parent. Wild type (WT) Littermate controls (C57B6-WT, DBA2-WT, BXD87-WT) shared the same genetic background but lacked the TSC1 knockout. Genotyping was performed on tail and toe snips collected prior to weaning. Data were collected from 45 mice in the resultant six groups. The table summarizes the counts by sex and genotype of the mice. 




 
Het
Het
WT
WT
 
 
 
 
 


Strain
Female
Male
Female
Male
Het
WT
Female
Male
Total


BXD87
7
3
2
5
10
7
9
8
17


DBA2
4
2
3
5
6
8
7
7
14


C57BG
4
2
6
2
6
8
10
4
14


Total
15
7
11
12
22
23
26
19
45










Electrodes were constructed with 6-pin Mill-Max strips attached to copper-tin wire leads. 







At approximately postnatal day 65, adult mice underwent implantation surgery. Mice were anesthetized with 1–2% isoflurane in oxygen and continually monitored for breathing rate and pain response. An incision was made at the top of the head to reveal lambda and bregma sutures of the skull. A needle was used to make six small burr holes in the skull where we placed skull screws (stainless steel). Copper-tin wire leads from the electrode were soldered onto the skull screws. The implant was sealed in place and covered to prevent discomfort or accidental removal. The six pin holes were exposed at the top. After the electrode was securely attached to the head, the mouse recovered for five days. After recovery, we attached a Pinnacle headmount (Pinnacle Technologies, Lawrence, KS) to the electrode implant and recorded EEG using Pinnacle data acquisition software that extracts live data via Bluetooth and concurrent video monitoring.










Signals were high-pass filtered at 1 Hz and sampled at a rate at 256 Hz. Three channels were recorded: 1) a right frontal signal relative to the reference signal, 2) a left frontal signal with the same reference, and 3) a bimodal parietal signal. Recording lasted five to seven days and the mouse was allowed to freely move, eat, and sleep in an open cage.

 Spontaneous seizures were identified electrographically by visual inspection and Sirrenia seizure detection software (Pinnacle Technologies, Lawrence, KS), and confirmed behaviorally with video monitoring offline (data not shown). Of the 45 mice, spontaneous seizures were identified in 3 mice of BXD87 Het genotype, with a total of 57 seizure events, averaging 5.12 minutes. Specifically, the first mouse had 10 events averaging 4 minutes, the second had 27 events averaging 6.46 minutes, and the third had 22 events averaging 5.15 minutes.  

In the three BXD87 mice with seizures, seizure start and end times and duration in each recording file are noted in the CSV file.