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Medial Septal Nucleus
The medial septal nucleus (MS) is one of the septal nuclei. Neurons in this nucleus give rise to the bulk of efferents from the septal nuclei. A major projection from the medial septal nucleus terminates in the hippocampal formation. It plays a role in the generation of theta waves in the hippocampus. Specifically, the GABAergic cells of the medial septum that act as theta pacemakers target dentate gyrus The dentate gyrus (DG) is part of the hippocampal formation in the temporal lobe of the brain, which also includes the hippocampus and the subiculum. The dentate gyrus is part of the hippocampal trisynaptic circuit and is thought to contribute t ..., CA3, and CA1 interneurons. Pacemaking MS interneurons express hyperpolarization-activated cyclic nucleotide-gated (HCN) channels which likely, at least partially, mediate their pacemaker properties. It is composed of GABAergic cells, glutamatergic cells, and cholinergic cells. Each cell-type carries out different functions. In ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Septal Nuclei
The septal area (medial olfactory area), consisting of the lateral septum and medial septum, is an area in the lower, posterior part of the medial surface of the frontal lobe, and refers to the nearby septum pellucidum. The septal nuclei are located in this area. The septal nuclei are composed of medium-size neurons which are classified into dorsal, ventral, medial, and caudal groups. The septal nuclei receive reciprocal connections from the olfactory bulb, hippocampus, amygdala, hypothalamus, midbrain, habenula, cingulate gyrus, and thalamus. The septal nuclei are essential in generating the theta rhythm of the hippocampus. The septal area (medial olfactory area) has no relation to the sense of smell, but it is considered a pleasure zone in animals. The septal nuclei play a role in reward and reinforcement along with the nucleus accumbens. In the 1950s, Olds & Milner showed that rats with electrodes implanted in this area will self-stimulate repeatedly (i.e., press a bar to rece ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hippocampal Formation
The hippocampal formation is a compound structure in the Temporal lobe#Medial temporal lobe, medial temporal lobe of the brain. It forms a c-shaped bulge on the floor of the temporal horn of the Lateral ventricles, lateral ventricle. There is no consensus concerning which brain regions are encompassed by the term, with some authors defining it as the dentate gyrus, the hippocampus proper and the subiculum; and others including also the Brodmann area 27, presubiculum, parasubiculum, and entorhinal cortex. The hippocampal formation is thought to play a role in memory, spatial navigation and control of attention. The neural layout and pathways within the hippocampal formation are very similar in all mammals. History and function During the nineteenth and early twentieth centuries, based largely on the observation that, between species, the size of the olfactory bulb varies with the size of the parahippocampal gyrus, the hippocampal formation was thought to be part of the olfactory sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theta Wave
Theta waves generate the theta rhythm, a neural oscillation in the brain that underlies various aspects of cognition and behavior, including learning, memory, and spatial navigation in many animals. It can be recorded using various electrophysiological methods, such as electroencephalogram (EEG), recorded either from inside the brain or from electrodes attached to the scalp. At least two types of theta rhythm have been described. The hippocampal theta rhythm is a strong oscillation that can be observed in the hippocampus and other brain structures in numerous species of mammals including rodents, rabbits, dogs, cats, and marsupials. ''"Cortical theta rhythms"'' are low-frequency components of scalp EEG, usually recorded from humans. Theta rhythms can be quantified using quantitative electroencephalography (qEEG) using freely available toolboxes, such as, EEGLAB or the Neurophysiological Biomarker Toolbox (NBT). In rats, theta wave rhythmicity is easily observed in the hippoca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GABAergic
In molecular biology and physiology, something is GABAergic or GABAnergic if it pertains to or affects the neurotransmitter GABA. For example, a synapse is GABAergic if it uses GABA as its neurotransmitter, and a GABAergic neuron produces GABA. A substance is GABAergic if it produces its effects via interactions with the GABA system, such as by stimulating or blocking neurotransmission. A GABAergic or GABAnergic agent is any chemical that modifies the effects of GABA in the body or brain. Some different classes of GABAergic drugs include agonists, antagonists, modulators, reuptake inhibitors and enzymes. See also * GABA reuptake inhibitor * Adenosinergic * Adrenergic * Cannabinoidergic * Cholinergic * Dopaminergic * Glycinergic * Histaminergic * Melatonergic * Monoaminergic * Opioidergic * Serotonergic Serotonergic () or serotoninergic () means "pertaining to or affecting serotonin". Serotonin is a neurotransmitter. A synapse is serotonergic if it uses serotonin as its neurotr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dentate Gyrus
The dentate gyrus (DG) is part of the hippocampal formation in the temporal lobe of the brain, which also includes the hippocampus and the subiculum. The dentate gyrus is part of the hippocampal trisynaptic circuit and is thought to contribute to the formation of new episodic memories, the spontaneous exploration of novel environments and other functions. It is notable as being one of a select few brain structures known to have significant rates of adult neurogenesis in many species of mammals, from rodents to primates. Other sites of adult neurogenesis include the subventricular zone, the striatum and the cerebellum. However, whether significant neurogenesis exists in the adult human dentate gyrus has been a matter of debate. 2019 evidence has shown that adult neurogenesis does take place in the subventricular zone and in the subgranular zone of the dentate gyrus. Structure The dentate gyrus, like the hippocampus, consists of three distinct layers: an outer molecular layer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HCN Channel
Hyperpolarization-activated cyclic nucleotide–gated (HCN) channels are integral membrane proteins that serve as nonselective voltage-gated ion channel, voltage-gated cation ion channel, channels in the plasma membranes of heart and brain cells. HCN channels are sometimes referred to as pacemaker channels because they help to generate rhythmic activity within groups of heart and brain cells. HCN channels are activated by membrane hyperpolarization, are permeable to and , and are constitutively open at voltages near the resting membrane potential. HCN channels are encoded by four genes (HCN1, HCN2, 2, HCN3, 3, HCN4, 4) and are widely expressed throughout the heart and the central nervous system. The electric current, current through HCN channels, designated ''I''f or ''I''h, plays a key role in the control of cardiac and neuronal cardiac rhythmicity, rhythmicity and is called the pacemaker current or "funny" current. Expression of single isoforms in heterologous expression, heterol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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