GABAergic medial septal neurons with low-rhythmic firing innervating the dentate gyrus and hippocampal area CA3.

08:00 EDT 29th March 2019 | BioPortfolio

Summary of "GABAergic medial septal neurons with low-rhythmic firing innervating the dentate gyrus and hippocampal area CA3."

The medial septum implements cortical theta oscillations, a 5-12 Hz rhythm associated with locomotion and paradoxical sleep, reflecting synchronization of neuronal assemblies e.g. place cell sequence coding. Highly rhythmic burst-firing parvalbumin-positive GABAergic medial septal neurons are strongly coupled to theta oscillations and target cortical GABAergic interneurons, contributing to coordination within one or several cortical regions. However, a large population of medial septal neurons of unidentified neurotransmitter phenotype and with unknown axonal target areas fire with a low degree of rhythmicity. We investigated whether low-rhythmic firing neurons (LRNs) innervated similar or different cortical regions to high-rhythmic neurons (HRNs) and assessed their temporal dynamics in awake male mice. The majority of LRNs were GABAergic and parvalbumin-immunonegative, some expressing calbindin; they innervated interneurons mostly in the dentate gyrus (DG) and CA3. Individual LRNs showed several distinct firing patterns during immobility and locomotion, forming a parallel inhibitory stream for the modulation of cortical interneurons. Despite their fluctuating firing rates, the preferred firing phase of LRNs during theta oscillations matched the highest firing probability phase of principal cells in the DG and CA3. In addition, as a population, LRNs were markedly suppressed during hippocampal sharp-wave ripples, had a low burst incidence, and several of them did not fire on all theta cycles. Thus, CA3 receives GABAergic input from both HRNs and LRNs, but the DG receives mainly LRN input. We propose that distinct GABAergic LRNs contribute to changing the excitability of the DG and CA3 during memory discrimination via transient disinhibition of principal cells.For the encoding and recall of episodic memories, nerve cells in the cerebral cortex are activated in precisely timed sequences. Rhythmicity facilitates the coordination of neuronal activity, and these rhythms are detected as oscillations of different frequencies, such as 5-12 Hz theta oscillations. Degradation of these rhythms, e.g. through neurodegeneration, causes memory deficits. The medial septum, a part of the basal forebrain that innervates the hippocampal formation, contains high-rhythmic and low-rhythmic firing neurons, which may contribute differentially to cortical neuronal coordination. We discovered that GABAergic low-rhythmic neurons preferentially innervate the dentate gyrus and the CA3 area of the hippocampus, regions important for episodic memory. These neurons act in parallel with the high-rhythmic neurons, mostly via transient inhibition of inhibitory neurons.


Journal Details

This article was published in the following journal.

Name: The Journal of neuroscience : the official journal of the Society for Neuroscience
ISSN: 1529-2401


DeepDyve research library

PubMed Articles [3439 Associated PubMed Articles listed on BioPortfolio]

Analysis of excitatory and inhibitory neuron types in the inferior colliculus based on Ih properties.

The inferior colliculus (IC) is a large midbrain nucleus that integrates inputs from many auditory brainstem and cortical structures. Despite its prominent role in auditory processing, the various cel...

GABAergic mediation of hippocampal theta rhythm induced by stimulation of the vagal nerve.

The key question to be answered in the present study was whether the medial septal GABAergic receptors are engaged in the pharmacological profile of VNS-induced hippocampal theta rhythm. It was demons...

Enhanced AMPA receptor-mediated excitatory transmission in the rodent rostromedial tegmental nucleus following lesion of the nigrostriatal pathway.

The GABAergic rostromedial tegmental nucleus (RMTg) has reciprocal connections with the dopaminergic ventral tegmental area and substantia nigra pars compacta (SNc), and is involved in inhibitory cont...

Serotonin receptors in the rat dorsal raphe nucleus exert a GABA-mediated tonic inhibitory control on serotonin neurons.

The central serotonin receptor (5-HTR) is a well-established modulator of dopamine (DA) neuron activity in the rodent brain. Recent studies in rats have shown that the effect of 5-HTR antagonists on a...

Neurons Expressing Estrogen Receptor α Differentially Innervate the Periaqueductal Gray Matter of Female Rats.

The periaqueductal gray matter (PAG) is a brainstem site involved in distinct autonomic and behavioral responses. Among them, the motor control of female sexual behavior, including lordosis, is well d...

Clinical Trials [623 Associated Clinical Trials listed on BioPortfolio]

Closure of Atrial Septal Defects With the AMPLATZER Septal Occluder - Post Approval Study

The purpose of this study is to prospectively evaluate the incidence of hemodynamic compromise and to obtain long-term survival data on patients with the AMPLATZER Septal Occluder

Single Neurons Responses During Visual Recognition in Epileptic Patients

The purpose is to evaluate specific capacities of face detection of individual neurons by comparison with their capacity of object detection in medial temporal lobe and ventral temporal co...

Stitch Closure of PFO and Septal Repair

The purpose of the STITCH study is to evaluate closure rates of clinically relevant septal defects, including patent foramen ovale (PFO), Atrial Septal Defects (ASD - less than 1 cm with r...

ENTact™ Septal Stapler Shelf Life Extension

This study is a prospective, limited-use evaluation of the ENTact™ Septal Stapler for tissue approximation utilizing staples with extended shelf life. The ENTact™ Septal Stapler will be ...

Safety and Effectiveness Study of the Solysafe Septal Occluder

Prospective mono-center clinical study to evaluate the safety and effectiveness of an intracardiac septal closure device in patients with atrial septum defect (ASD)

Medical and Biotech [MESH] Definitions

Networks of nerve cells that control the firing patterns of MOTOR NEURONS to produce rhythmic movements such as MASTICATION; WALKING; SWIMMING; RESPIRATION; and PERISTALSIS.

Neurons whose primary neurotransmitter is GAMMA-AMINOBUTYRIC ACID.

Neural nuclei situated in the septal region. They have afferent and cholinergic efferent connections with a variety of forebrain and brainstem areas including the hippocampus, the lateral hypothalamus, the tegmentum, and the amygdala. Included are the dorsal, lateral, medial, and triangular septal nuclei, septofimbrial nucleus, nucleus of diagonal band, nucleus of anterior commissure, and the nucleus of stria terminalis.

Thin layer of WHITE MATTER mostly of GABAERGIC NEURONS located between the PUTAMEN and the CLAUSTRUM.

The ligament that travels from the medial epicondyle of the FEMUR to the medial margin and medial surface of the TIBIA. The medial meniscus is attached to its deep surface.

Quick Search


DeepDyve research library

Relevant Topic

Sleep Disorders
Sleep disorders disrupt sleep during the night, or cause sleepiness during the day, caused by physiological or psychological factors. The common ones include snoring and sleep apnea, insomnia, parasomnias, sleep paralysis, restless legs syndrome, circa...

Searches Linking to this Article