0000000000305875
AUTHOR
G. Caravaglios
Accumbens-caudate-septal circuit as a system for hippocampal regulation: involvement of a GABAergic neurotransmission.
Hippocampal-based epileptiform activity may reach the basal ganglia via the nucleus accumbens. Previous data suggested that caudate nucleus is able to influence hippocampal epilepsy, probably sending a projection to the septum. In order to test the hypothesis of a retrograde activation of accumbens-caudate pathway in hippocampal regulation, we electrically stimulated both caudate nucleus and nucleus accumbens and studied modifications of hippocampal EEG in the feline focal epilepsy model. We also performed bilateral electrolytic lesion of nucleus accumbens and repeated caudate stimulation. Results showed that nucleus accumbens stimulation was ineffective in modifying hippocampal epilepsy; o…
Being the Family Caregiver of a Patient With Dementia During the Coronavirus Disease 2019 Lockdown
Background: Family caregivers of patients with dementia are at high risk of stress and burden, and quarantine due to the coronavirus disease 2019 (COVID-19) pandemic may have increased the risk of psychological disturbances in this population. The current study was carried out during the national lockdown declared in March 2020 by the Italian government as a containment measure of the first wave of the coronavirus pandemic and is the first nationwide survey on the impact of COVID-19 lockdown on the mental health of dementia informal caregivers.Methods: Eighty-seven dementia centers evenly distributed on the Italian territory enrolled 4,710 caregiver–patient pairs. Caregivers underwent a tel…
EEG Resting-State Functional Networks in Amnestic Mild Cognitive Impairment.
Background. Alzheimer’s cognitive-behavioral syndrome is the result of impaired connectivity between nerve cells, due to misfolded proteins, which accumulate and disrupt specific brain networks. Electroencephalography, because of its excellent temporal resolution, is an optimal approach for assessing the communication between functionally related brain regions. O bjective. To detect and compare EEG resting-state networks (RSNs) in patients with amnesic mild cognitive impairment (aMCI), and healthy elderly (HE). Methods. We recruited 125 aMCI patients and 70 healthy elderly subjects. One hundred and twenty seconds of artifact-free EEG data were selected and compared between patients with aM…
Dopaminergic control of feline hippocampal epilepsy: A nigrophippocampal pathway
Abstract Substantia nigra is a mesencephalic structure inserted along several circuits which appear to play a key role in epilepsy. In previous researches we postulated that substantia nigra pars compacta (SNpc) may be the site of a precise control of hippocampal epilepsy while substantia nigra pars reticulata (SNpr) may exert a modulation of both neocortical epilepsy and spreading of hyperactivity toward a motor target. In order to better understand mechanisms subserving nigral action in feline hippocampal epilepsy we electrically stimulated SNpc (dopaminergic), before and after sulpiride (dopamine receptor-antagonist) intravenous injection. Furthermore we compared hippocampal epileptiform…
Gabapentin in the treatment of hemifacial spasm
Objectives To evaluate the efficacy of gabapentin in the treatment of hemifacial spasm. Material and methods Twenty-three patients with hemifacial spasm not suitable for surgery or therapy with botulinum toxin were treated with gabapentin. The main efficacy parameter was the percentage of spasm reduction. Results A clinically significant reduction of spasms was obtained by 16 patients. Conclusion Gabapentin was effective and safe in reducing hemifacial spasm in 16 out 23 (69.6%) patients.
Evidence of a contralateral motor influence on reciprocal inhibition in man
The role of contralateral movement on both H reflex and reciprocal inhibition was studied. In normal men H reflex was induced by median nerve stimulation. Reciprocal inhibition was achieved through stimulation of the antagonist radial nerve. On this basis the effects of contralateral arm movement were analized. Furthermore the putative influence of exteroceptive origin was also verified by means of digit stimulation. Results showed that contralateral arm movement did not affect H reflex amplitude; on the contrary, it was able to enhance reciprocal inhibition induced by extensors on flexors. Study of cutaneous afferents demonstrated that contralateral digit stimulation failed to elicit modif…
Electrophysiological and Iontophoretic Aspects of the Habenular Influence on Hippocampal Neurones
In previous experimental studies, carried out on cats, we demonstrated that electrical stimulation of lateral habenula (LH) at 0.5-3.0 Hz or 5-20 Hz had a double effect (low frequency-excitation; high frequency-inhibition) on the spontaneous firing rate of single hippocampal neurones. Our results, in agreement with similar case studies, allowed us to hypothesise that in the habenular modulation of the hippocampus the raphe nucleus is probably involved. In fact, all the effects of LH stimulation were antagonised by the iontophoretic intrahippocampal application of methysergide. In the present series of experiments, performed on rats, it was possible to demonstrate that LH stimulation at 1-10…
A feature of caudate control of focal hippocampal epilepsy: evidence for an anterograde pathway
Previous experimental evidences showed that the caudate nucleus has a modulatory effect on hippocampal epilepsy. The caudate's regulating action might reach the hippocampus either via the septal region or, retrogradely, via the accumbens nucleus. In order to obtain new data about the pathway involved in caudate hippocampal influence the spreading of abnormal activity towards the nucleus accumbens was studied. Furthermore the effects of caudate stimulation in animals with electrolytic lesions of the nucleus accumbens were analyzed. It was observed that abnormal penicillin-induced activity spreaded from the hippocampus to the nucleus accumbens in about 30 minutes. In animals with and without …
Auditory event-related potentials (P300) in epileptic patients.
Auditory event-related potentials (AERPs) were recorded during an auditory oddball paradigm in 108 epileptics and in 32 healthy controls. P300 latency varied in relationship with age only in controls. Symptomatic epileptics had significantly prolonged P300 mean latency compared to those without detectable brain lesion(s) on MR scan. Moreover, these latter patients were compared on the basis of epilepsy duration, type of seizure, seizure frequency and antiepileptic treatment; the application of a multiple regression model showed a significant relationship between P300 latency prolongation and epilepsy duration, seizure frequency and polytherapy.
Bilateral reciprocal organisation in man: focus on IA interneurone
The H reflex of flexor carpi radialis and radial-induced reciprocal inhibition were recorded in normal subjects during conditioning stimulation of the contralateral median or radial nerves. It was found that stimulation of the contralateral median nerve enhanced the degree of reciprocal inhibition exerted by the radial nerve on the median nerve, while contralateral radial nerve stimulation reduced the reciprocal inhibition exerted by the extensor on the flexor. In two subjects in which a pure extensor H reflex was recorded specular features were observed following contralateral median and radial stimulation. These findings are considered to be the electrophysiological manifestation of contr…
Electrophysiological and microiontophoretic analysis of the habenulo-hippocampal circuit.
In the cat, the effects of lateral habenula stimulation, at different ranges of frequency, on hippocampal units were studied. Habenular stimulation at low frequency excited, while at high frequency inhibited the greater part of hippocampal units. Moreover, in order to clarify the possible pathway involved in the habenulo-hippocampal circuit, the effects of iontophoretic acetylcholine and serotonin on hippocampal units were compared with those of habenular stimulation. Iontophoretic acetylcholine induced both excitatory and inhibitory responses while serotonin induced only inhibitory responses. Iontophoretic atropine blocked the effects of acetylcholine ejection but did not antagonize stimul…