• One much-cited 2002 study of twins showed that some people who wind up with PTSD have smaller hippocampi to start with. (psmag.com)
  • However, theta activity can also be generated in the ventral hippocampus itself during anxiety- and fear-related behaviors. (diva-portal.org)
  • In this thesis I present compelling in vitro and in vivo evidence that a subpopulation of OLM interneurons (defined by the Chrna2-cre line) distinctively enriched in the CA1 region of the ventral hippocampus is implicated in LTP function (paper I,II), information control (paper V) and the induction of theta activity that is under cholinergic control (paper IV). (diva-portal.org)
  • Four rats were equipped with single ( n = 2) or double ( n = 2) 16-site silicon probes (with recording sites at 100-μm vertical spacing) for simultaneous recording of unit activity and field potentials in different cortical layers and hippocampus. (pnas.org)
  • We have analyzed the developmental molecular programs of the mouse hippocampus, a cortical structure critical for learning and memory, by means of large-scale DNA microarray techniques. (pnas.org)
  • When they knocked out CB1 only in glutamatergic cortical neurons (including hippocampus, neocortex, and amygdala), mice still experienced stronger seizures compared to their wild-type littermates. (alzforum.org)
  • Conditional deletion of the CB1 gene either in cortical glutamatergic neurons or in forebrain GABAergic neurons, as well as virally induced deletion of the CB1 gene in the hippocampus, demonstrate that the presence of CB1 receptors in glutamatergic hippocampal neurons is both necessary and sufficient to provide substantial endogenous protection against kainic acid (KA)-induced seizures. (nih.gov)
  • DNA nick end-labeling at 3 days following ischemia showed DNA fragmentation in neurons limited to the CA1 region of hippocampus following 5 min ischemia, while DNA fragmentation was detected in CA1, CA3, dentate gyrus and cortical neurons following 10 min ischemia. (nih.gov)
  • This result was subsequently replicated in numerous studies demonstrating activity in the hippocampus and associated parahippocampal cortical regions during encoding of new information, including work showing that the magnitude of hippocampal activity during encoding of stimuli correlates with recognition of stimuli in subsequent memory tests. (wikipedia.org)
  • In rats, the most frequently studied species, theta wave rhythmicity is easily observed in the hippocampus, but can also be detected in numerous other cortical and subcortical brain structures. (wikipedia.org)
  • These different theories have since been combined, as it has been shown that the firing patterns can support both navigation and memory Cortical theta rhythms observed in human scalp EEG are a different phenomenon, with no clear relationship to the hippocampus. (wikipedia.org)
  • The afferent connections of the hippocampus, so it's receiving information from the amygdala, so that's going in, all parts of the sensory cortex, are coming in, the cingulate gyrus that's on the medial surface of the brain, it's sending information into the hippocampus as is the frontal cortex. (coursera.org)
  • Information flowing out of the hippocampus or efferent information, is going to go back to the amygdala, back to the sensory cortex, back to the frontal cortex, it's also going to go to the hypothalamus, which is pictured here. (coursera.org)
  • Here, we show a robust correlation of neuronal discharges between the somatosensory cortex and hippocampus on both slow and fine time scales in the mouse and rat. (pnas.org)
  • To address this issue, we used multisite recording of unit and field activity in the hippocampus and somatosensory cortex. (pnas.org)
  • The somatosensory cortex was chosen because it is the most prominent source of sensory information in the rat ( 24 ), and, unlike the prefrontal cortex ( 25 ), it does not receive monosynaptic input from the hippocampus. (pnas.org)
  • Here, we demonstrate temporal coupling of neuronal activity between the somatosensory cortex and hippocampus on both slow and fine time scales and show that neocortical activity can time the occurrence of hippocampal sharp waves and ripples. (pnas.org)
  • The hippocampus is a section of the brain located below the cerebral cortex . (fact-index.com)
  • The hippocampus was originally associated, incorrectly, with the sense of smell, which is actually processed by the olfactory cortex . (wisegeek.com)
  • Prevailing research posits that recollection and familiarity memories involve different regions in the brain's medial temporal lobe: the hippocampus for recollection, the adjacent perirhinal cortex for familiarity. (ucsd.edu)
  • In the middle of the brain, connected to the cortex , is the hippocampus. (braingle.com)
  • Intermittent ethanol treatment causes a decrease in expression of the dopamine receptor type 2 (D2R) and a decrease in phosphorylation of 2B subunit of the NMDA receptor (NMDAR2B) in the prefrontal cortex, hippocampus, nucleus accumbens, and for only D2R the striatum. (wikipedia.org)
  • Scientists believe that a small hippocampus may result in poor communication between nerves in the brain. (wisegeek.com)
  • However, people who had a first episode of major depression (34 per cent of study subjects with major depression) did not have a small hippocampus than healthy individuals, indicating that the changes are due to the adverse effects of depressive illness on the brain. (eurekalert.org)
  • Small Hippocampus Associated with Depression in the Elderly: Risk Factor or Shrinkage? (alphagalileo.org)
  • That pointed to a small hippocampus as a biological vulnerability. (psmag.com)
  • A and B ) Scatterplots of the association between percent change in left and right hippocampus volume and percent change in aerobic fitness level from baseline to after intervention. (pnas.org)
  • C and D ) Scatterplots of percent change in left and right hippocampus volume and percent change in BDNF levels. (pnas.org)
  • E and F ) Scatterplots of percent change in left and right hippocampus and percent change in memory performance. (pnas.org)
  • A subsequent morphological comparison of specimens collected from the North Atlantic Ocean that had been previously assigned to P. minuta and P. hippocampus was undertaken by Seapy (2000). (tolweb.org)
  • Hippocampus Press homepage Publishers Weekly Fiction Book Review, "H. P. Lovecraft: Collected Fiction: A Variorum Edition" ISFB, "Series: Collected Essays of H. P. Lovecraft" The H. P. Lovecraft Archive, "The Ancient Track: The Complete Poetical Works of H. P. Lovecraft (second revised edition)" 2011 Bram Stoker Award nominees and winners Archived 2000-08-24 at the Wayback Machine. (wikipedia.org)
  • The hippocampus was further detailed in "The Ecology of the Hippocampus" in Dragon #273 (July 2000). (wikipedia.org)
  • In primate brains, including humans, the portion of the hippocampus near the base of the temporal lobe is much broader than the part at the top. (wikipedia.org)
  • The hippocampus is required for short-term topographical memory in humans. (nih.gov)
  • Humans with hippocampus damage also show selective memory impairments. (jneurosci.org)
  • Studies in rodents have found that the hippocampus, which in humans seems particularly sensitive to age-related shrinkage, can be enlarged by exercise. (dana.org)
  • In adult humans about 700 new neurons are added in the hippocampus every day. (wikipedia.org)
  • Exercise training increases cerebral blood volume ( 15 ) and perfusion of the hippocampus ( 16 ), but the extent to which exercise can modify the size of the hippocampus in late adulthood remains unknown. (pnas.org)
  • We predicted that 1 y of moderate-intensity exercise would increase the size of the hippocampus and that change in hippocampal volume would be associated with increased serum BDNF and improved memory function. (pnas.org)
  • We found that the exercise intervention was effective at increasing the size of the hippocampus. (pnas.org)
  • There are still studies that need to be done on this but it's very possible that depression causes people to think irrationally because of this reduction in the size of the hippocampus. (wisegeek.com)
  • All of those would together increase the size of the hippocampus," Mattson says. (dana.org)
  • The stratum lucidum of the hippocampus is also a layer of the hippocampus between the stratum pyramidale and the stratum radiatum. (wikipedia.org)
  • Similar to spiny neurons, aspiny neuron dendrites "branch extensively in stratum lucidum and stratum radiatum of CA3", in contrast to spiny neurons, however, some dendrites "traversed stratum pyramidale and entered stratum oriens", the second deepest layer of the hippocampus. (wikipedia.org)
  • Particularly in dentate gyrus, new nerve cells are formed locally at the border between the granular layer and the hilus (SGZ), migrate short distances along the inner granular zone (IGZ), and extend long axonal projections to the CA3 pyramidal cell layer of the hippocampus [ 5 , 6 ]. (hindawi.com)
  • In this review, we will discuss the idea that the hippocampus may be involved in both memory and perception, contrary to theories that posit functional and neuroanatomical segregation of these processes. (frontiersin.org)
  • The LC-induced inhibition was antagonized by iontophoretic sotalol, but not by phentolamine, suggesting that noradrenaline derived from the LC inhibits the Acc neurons receiving input from the hippocampus, probably acting on a beta-adrenergic receptor. (google.com)
  • It has been suggested that hippocampal dysfunction is involved in schizophrenia and this convergence of input from the hippocampus onto the same neurons that are post-synaptic to the dopaminergic input, which presumably originates from neurons in the ventral tegmental area, may provide an anatomical basis for the therapeutic effects of neuroleptic drugs which are dopamine antagonists. (google.com)
  • The hippocampus itself, has been called cornu ammonis or ammon's horn and so, if you're ever reading papers about the hippocampus, you may see it referred to as CA, meaning cornu ammonis or ammon's horn and there are subdivisions even within the hippocampus, their CA one, two and three which are subdivisions of the hippocampus that have different synaptic connections. (coursera.org)
  • The latter view is strengthened by recent evidence that neurogenesis in the adult hippocampus may ease the removal of old memories and increase the efficiency of forming new memories. (wikipedia.org)
  • Chronic use of antidepressant increased neurogenesis in the hippocampus of rats. (wikipedia.org)
  • Declarative memory, the conscious recollection of past experiences, is known to involve the hippocampus. (nature.com)
  • Eichenbaum, H. Conscious awareness, memory and the hippocampus. (nature.com)
  • Bliss TVP and Collingridge GL (1993) A synaptic model of memory: long‐term potentiation in the hippocampus. (els.net)
  • Hirsh, R. The hippocampus and contextual retrieval of information from memory: A theory. (springer.com)
  • The hippocampus is involved in the storage of long-term memory, which includes all past knowledge and experiences. (healthline.com)
  • In particular, the hippocampus seems to play a major role in declarative memory, the type of memory involving things that can be purposely recalled, such as facts or events. (healthline.com)
  • The hippocampus is not involved with short-term memory and procedural memory types (memory of how to do motor actions, like walking). (healthline.com)
  • The EC has dual functions in processing information for explicit memory storage: First, it is the main input to the hippocampus. (wikipedia.org)
  • The hippocampus shrinks in late adulthood, leading to impaired memory and increased risk for dementia. (pnas.org)
  • Deterioration of the hippocampus precedes and leads to memory impairment in late adulthood ( 1 , 2 ). (pnas.org)
  • Healthline explains the hippocampus directs a human's declarative memory, or the collected experiences and gathered knowledge of the person. (reference.com)
  • Psychologists and neuroscientists are not entirely sure of the precise role of the hippocampus, but, in general, agree that it has an essential role in the formation of new memories about experienced events ( episodic or autobiographical memory ). (bionity.com)
  • Some researchers prefer to consider the hippocampus as part of a larger medial temporal lobe memory system responsible for general declarative memory (memories that can be explicitly verbalized - these would include, for example, memory for facts in addition to episodic memory). (bionity.com)
  • Some evidence supports the idea that, although these forms of memory often last a lifetime, the hippocampus ceases to play a crucial role in the retention of the memory after a period of consolidation . (bionity.com)
  • It is because it attacks the hippocampus first that Alzheimer's disease is first discovered by the patient's memory loss. (fact-index.com)
  • fify-- The hippocampus is important both for learning and memory, so there is no doubt that changes in its function would have consequences for these activities. (wisegeek.com)
  • Despite the significance of the hippocampus in learning and memory, our understanding of the genetic programs underlying the developing hippocampus is quite limited. (pnas.org)
  • We know from neuropsychological evidence, therefore, that the hippocampus is critical to short-term memory for associative information. (jneurosci.org)
  • A synaptic model of memory: long-term potentiation in the hippocampus. (nih.gov)
  • Long-term potentiation of synaptic transmission in the hippocampus is the primary experimental model for investigating the synaptic basis of learning and memory in vertebrates. (nih.gov)
  • Nonetheless, the hippocampus may be specialized for allocentric topographical processing, which impacts on short-term memory or even perception. (nih.gov)
  • It's there that cholinergic and GABA neurons -- associated with Alzhemier's and other neurological disorders, from epilepsy to addiction -- connect the medial septum to the hippocampus, which plays a vital role in memory. (wired.co.uk)
  • Post-transplant, the mice scored better in traditional memory tests, suggesting the function of the medial septum had been restored, along with improved hippocampus function. (wired.co.uk)
  • For a memory to get into long-term storage , it must be selected by the hippocampus. (braingle.com)
  • For example, some theories hold that the hippocampus is used to maintain a memory trace of the CS so that it can be associated with the US later in time. (jneurosci.org)
  • Since the ground-breaking work of Scoville and Milner (1957) , the hippocampus has been considered to be an integral component of a medial temporal lobe (MTL) memory system. (frontiersin.org)
  • So far, the assumption was that the hippocampus was more or less mature by the age of six years and further memory development was only dependent on the maturation of the neocortex, explains Nora Newcombe. (innovations-report.com)
  • Stern published the earliest functional magnetic resonance imaging study showing robust increases in blood flow to the hippocampus during memory encoding. (wikipedia.org)
  • Prior to this study, imaging studies did not observe robust changes in hippocampus during verbal memory tasks, but this study demonstrated clear increases in blood flow during encoding of complex novel visual scenes. (wikipedia.org)
  • It is hypothesized that DHA and arachidonic acid could improve memory function by interacting with FFA1 in the hippocampus neurons. (wikipedia.org)
  • Without the medial temporal lobe, one is able to form new procedural memories (such as playing the piano) but cannot remember the events during which they happened (See the hippocampus and memory). (wikipedia.org)
  • Research indicates that mice with a genetic deletion of the type I IL-1 receptor display markedly impaired hippocampal-dependent memory functioning and Long-term potentiation, although memories that do not depend on the integrity of the hippocampus seem to be spared. (wikipedia.org)
  • She concluded that the hippocampus is at the core of orienting reflex and works as a comparator determining whether information should be stored in memory (if it is new) or ignored (if it is old). (wikipedia.org)
  • Although rats with excitotoxic lesions of the hippocampus could not learn a standard trace fear-conditioning paradigm, lesioned rats trained on CTC showed significant conditioning, at levels similar to those with sham surgeries. (jneurosci.org)
  • In the hippocampus, granule cells of the dentate gyrus form distinctive unmyelinated axons that project along the mossy fiber pathway to the Cornu Ammonis area 3 (CA3). (wikipedia.org)
  • Granule cells in the DG project to the CA3 field of the hippocampus via the mossy fiber (mf) pathway. (nih.gov)
  • A ) Mossy fiber axons (short arrows) and synaptic boutons en passant (long arrows) within the stratum lucidum. (nih.gov)
  • It is composed of a densely packed bundle of mossy fibers (unmyelinated) and spiny and aspiny interneurons that lie immediately above the CA3 pyramidal cell layer in the hippocampus, and immediately below the stratum radiatum. (wikipedia.org)