bioRxiv Science⌕ Search

Biology subjects

Rulhe, C.

Publications and source records attributed to Rulhe, C..

2 recordsLinked to original sources

Daily intermittent fasting is an effective multiscale treatment in preclinical models of absence epilepsy

Absence epilepsy (AE) is characterized by brief but frequent seizures with loss of consciousness. Existing treatments have heavy side effects, are only partially effective and do not address the comorbidities, including cognitive and social deficits. A tripartite link between seizures, cognitive deficits and diet has been established. We focused on intermittent fasting (IF), a regime where daily periods of fasting alternate with periods of food intake, with no restrictions in the type or quantity of food consumed. To date, the effects of IF on infantile epilepsy have not been addressed. We evaluated the therapeutic potential of a daily, one-month protocol of IF on three established mouse models of AE: the Grm7AAA KI mouse, the Scn2a haploinsufficiency mouse and the pharmacologically-induced AY-9944 mouse model. We show a reduction of the seizure frequency in all models, as well as an improvement of the sociability deficits observed in two of the models, with no adverse effects. Focusing on the Grm7AAA KI model, we performed RNA sequencing in a one of the key brain areas of the absence seizure circuit, the thalamus. We detected a deregulation of genes involved in vascularization associated with the development of malformed blood vessels in epileptic mice. Along with its anti-seizure effects, IF was able to counteract both abnormal gene expression and vessel morphology. This study demonstrates for the first time the positive effects of IF on AE and could facilitate the implementation of the diet in clinical trials.

neuroscience↗

T-type calcium channels participate in intrinsic and synaptic activity of PKCγ neurons of the dorsal horn of the spinal cord during chronic pain

ABSTRACTThe disinhibition of the excitatory PKC{gamma} interneurons plays a central role during mechanical allodynia in the dorsal horn of the spinal cord, routing harmless information to nociceptive pathways. The T-type calcium channel Cav3.2, necessary for mechanical and cold allodynia, is found in most PKC{gamma} neurons of the spinal cord. In this study, the role of Cav3.2 in PKC{gamma} neurons was studied after its pharmacological inhibition and its conditional deletion (KO) in Cav3.2GFP-Flox KI x PKC{gamma}-CreERT2 x Ai14 mice in normal conditions and in the spared-nerve-injury (SNI) model of neuropathic pain. Conditional deletion of Cav3.2 increased the hind-paw basal mechanical sensitivity before surgery, and decreased mechanical pain 7 days, but not 28 days, after surgery. At the cellular level, Cav3.2 participated in the low-threshold currents of PKC{gamma} neurons and the T-type calcium current of PKC{gamma} neurons was decreased in KO mice as compared to wild-type (WT). This loss did not convert into proportional alterations in subthreshold properties including "rebound" potentials, suggesting the involvement of other T-type channels. Action potential kinetics and firing properties seemed similar in WT and KO mice too, but rebound potentials were diminished in the SNI model in WT but not in KO mice. In addition, the modulations of firing properties induced by T-type channel pharmacological blocker Z944 observed in WT mice were absent in KO mice and after SNI. Furthermore, the pairing of action potentials was modified after SNI in WT mice, and not in KO mice. At the synaptic level, excitatory currents were lowered 7- and 28-days after surgery, while inhibitory currents were lowered only at 28 days. These changes were not found in Cav3.2-ablated neurons. Miniature currents analysis indicated that Cav3.2 was involved in both excitatory and inhibitory synaptic transmissions at the level of PKC{gamma} neurons. Surprisingly, Z944 did not mimic the effects of Cav3.2 ablation in PKC{gamma} neurons, suggesting distinct and eventually opposite roles of other T-type calcium channels. Altogether, our results show that Cav3.2 is not mandatory for firing of PKC{gamma} neurons of the dorsal horn of the spinal cord, but that it participates to the SNI-induced changes in their intrinsic and synaptic activity, including changes in their excitatory and inhibitory controls. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=147 SRC="FIGDIR/small/627933v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@1a297daorg.highwire.dtl.DTLVardef@19f7a76org.highwire.dtl.DTLVardef@120f688org.highwire.dtl.DTLVardef@119658e_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗