echoasebo.blogg.se - Hippocampus anatomy lab model

Role in memoryĭrawing of the neural circuitry of the rodent hippocampus. Golgi-stained neurons in the rodent hippocampus. There is now almost universal agreement that the hippocampus plays some sort of important role in memory however, the precise nature of this role remains widely debated. In the ensuing years, other patients with similar levels of hippocampal damage and amnesia (caused by accident or disease) have been studied as well, and literally thousands of experiments have studied the physiology of neural plasticity in the hippocampus. is now said to be the most intensively studied medical case in history. This case occasioned such enormous interest that H.M. was unable to consciously remember events that occurred after his surgery or for several years before it. The unexpected outcome was severe amnesia: H.M. Although it had precursors, this idea derived its main force from a very well-known report by Scoville and Milner of the results of surgical destruction of the hippocampus (in an attempt to relieve epileptic seizures), in a patient known as H.M. The second important line of thought relates the hippocampus to memory. The inhibition theory is not, however, very popular at present. Jeffrey Gray developed this line of thought into a full-fledged theory of the role of the hippocampus in anxiety. It derived much of its force from two observations: first, animals with hippocampal damage tend to be hyperactive second, animals with hippocampal damage often have difficulty learning to inhibit responses that they have previously been taught. The behavioral inhibition theory (caricatured by O'Keefe and Nadel as "step on the brakes!") was very popular up to the 1960s. Over the years, three main ideas of hippocampal function have dominated the literature: inhibition, memory, and space. There continues to be some interest in hippocampal olfactory responses, but almost nobody now believes that the primary function of the hippocampus is olfactory. Perhaps the earliest idea was that the hippocampus is involved in olfaction: this seems to have been suggested mainly by its location in the brain, next to the olfactory cortex.

3 Role in spatial memory and navigation.

People with extensive hippocampal damage may experience amnesia, that is, inability to form or retain new memories. Damage to the hippocampus can also result from oxygen starvation ( anoxia), encephalitis or mesial temporal lobe epilepsy. In Alzheimer's disease, the hippocampus is one of the first regions of the brain to suffer damage memory problems and disorientation appear among the first symptoms. The name, in fact, derives from the Greek word for seahorse ( Greek: hippos = horse, campos = sea). In humans, it has a curved and convoluted shape that reminded early anatomists of a seahorse. In rodents, where it has been studied most extensively, the hippocampus is shaped something like a banana. Humans and other mammals have two hippocampi, one in each side of the brain. It belongs to the limbic system and plays major roles in long term memory and spatial navigation. The hippocampus is a part of the forebrain, located in the medial temporal lobe. For the journal of the same name, see Hippocampus (journal) The location of the hippocampus in the human brain.