DOI: 10.5061/dryad.vdncjsz5k
title: Raw data obtained from multi-electrode electrophysiological recordings of hippocampal slices

description: Preclinical and clinical studies show that mild to moderate hypothermia is
 neuroprotective in sudden cardiac arrest, ischemic stroke, perinatal
 hypoxia/ischemia, traumatic brain injury and seizures. Induction of
 hypothermia largely involves physical cooling therapies, which induce
 several clinical complications, while some molecules have shown to be
 efficient in pharmacologically induced hypothermia (PIH). Neurotensin
 (NT), a 13 amino-acid neuropeptide that regulates body temperature,
 interacts with various receptors to mediate its peripheral and central
 effects. NT induces PIH when administered intracerebrally. However, these
 effects are not observed if NT is administered peripherally, due to its
 rapid degradation and poor passage of the blood brain barrier (BBB). We
 conjugated NT to peptides that bind the low-density lipoprotein receptor
 (LDLR) to generate “vectorized” forms of NT with enhanced BBB
 permeability. We evaluated their effects in epileptic conditions following
 peripheral administration. One of these conjugates, VH-N412, displayed
 improved stability, binding potential to both the LDLR and NTSR-1,
 rodent/human cross-reactivity and improved brain distribution. In a mouse
 model of kainate (KA)-induced status epilepticus (SE), VH-N412 elicited
 rapid hypothermia associated with anticonvulsant effects, potent
 neuroprotection and reduced hippocampal inflammation. VH-N412 also reduced
 sprouting of the dentate gyrus mossy fibers and preserved learning and
 memory skills in the treated mice. In cultured hippocampal neurons,
 VH-N412 displayed temperature-independent neuroprotective properties. To
 the best of our knowledge, this is the first report describing the
 successful treatment of SE with PIH. In all, our results show that
 vectorized NT may elicit different neuroprotection mechanisms mediated by
 hypothermia and/or by intrinsic neuroprotective properties.
description: Hippocampal slices (350 μm thick) were prepared from Sprague
 Dawley rats (n=3; 3-4 weeks old; Janvier Laboratories) and cut using a
 vibratome (Leica VT1200S) in an ice-cold oxygenated, modified ACSF,
 continuously aerated with 95% O<sub>2</sub> and 5%
 CO<sub>2</sub> and containing Glucose 11 mM,
 NaHCO<sub>3</sub> 25 mM, NaCl 126 mM, KCl 3.5 mM,
 NaH<sub>2</sub>PO<sub>4</sub> 1.2 mM,
 MgCl<sub>2</sub> 1.3 mM and CaCl<sub>2</sub> 2 mM.
 Slices were then incubated at RT for at least 1 H in ACSF. Recordings were
 performed on hippocampal slices using multielectrode arrays (MEA). Slices
 were continuously perfused with the oxygenated ACSF at the rate of 3
 mL/min with a peristaltic pump (MEA chamber volume: ~1 mL). KA (300 nM)
 and VH-N412 (0.1, 1 and 10 μm) were added to the perfusion solution to
 assess the effects of VH-N412 compound on KA-induced increase of neuronal
 firing. Complete solution exchange in the MEA chamber was achieved 20 s
 after the switch of solutions. The perfusion liquid was continuously
 pre-heated at 37°C just before reaching the MEA chamber with a
 heated-perfusion cannula (PH01, MultiChannel Systems, Reutlingen,
 Germany). The temperature of the MEA chamber was maintained at 37 ± 0.1°C
 with a heating element located in the MEA amplifier headstage. The spike
 numbers per second recorded at each electrode were averaged for 30 s slots
 and normalized to the mean spikes rate value at t = 20-30 min (10 last
 minutes of KA exposure period). Individual data from independent
 experiments were then pooled and the mean values of the normalized spike
 rates (± SEM) were plotted as a function of time (before and after
 exposure to VH-N412). The control values (KA alone) were averaged from 3
 rats, 3 slices and 18 electrodes. The dose response curves from the KA +
 VH-N412-treated slices were averaged from 3 rats, 4 slices and 25
 electrodes.
description: # Raw data obtained from multi-electrode electrophysiological recordings
 of hippocampal slices
 [https://doi.org/10.5061/dryad.vdncjsz5k](https://doi.org/10.5061/dryad.vdncjsz5k) ## Description of the data and file structure **Raw data obtained from multi-electrode recordings of hippocampal slices** ### Files and variables #### File: Electrophysiology\_RAW\_DATA.xlsx **Description:** The effects of VH-N412 on seizure activity led us to question whether the conjugate could modulate hippocampal neuronal hyperactivity induced by KA. We addressed this question using acute hippocampal slices that were recorded in the presence or absence of KA and VH-N412. ##### Variables * Mean values of the normalized spike rates (± SEM) were plotted as a function of time measured in minutes. ## Access information NA