Functions of limbic system :
A i.e. Emotion B i.e., Memory C i.e., Higher function Limbic System It is the entire neuronal circuit that controls emotional behaviour & motivational drives and a term that originally was used to describe bordering structures around basal region of cerebrum. Functions of hypothalamus Posterior Hypothalmus Pa of hypothalmus Vegetative & endocrinal function Behavioural function Lateral area * Thirst & hunger Stimulation centre increases general - Stimulation 1/t level of activity extreme hunger, voracious appetite l/t fighting & ove rage (1`. BP) & intense desire to search food deg - Damage causes lost desire for food and lethal starvation. Ventro medial * Satiety center Stimulation 1/t - Stimulation l/t satiety, decreased eating tranquility - Destruction 1/t voracibus appetite * Neuroendocrinal control Mamillary * Feeding reflexes body such as licking of lips & swallowing Functions of other pas Hippocampus - Almost any sensory experience activates some pa which intum distribute signals to other pa of limbic system. So it acts as a channel through which incoming sensory signals can initiate behavioural reactions for different purposes. - Becomes hyper excitable and gives off prolonged output signals. So in hippocampal seizures psychomotor (olfactory, visual, auditory, tactile) hallucinations cannot be suppressed as long as seizure persists. - Provides the drive that causes consolidation of long term memory (i.e. translates sho term memory into long term memory)Q. It determines the impoance of incoming sensory signal and has a critical decision making role that the information is likely to be committed to memory, making the mind rehearse over & over the new information until permanent storage takes place. - B/L damage I/t anterograde amnesia, with lost ability to establish memory lasting longer then few minutes. Amygdala - Coicomedial nuclei concerned with olfaction - Basolateral nuclei is more developed in humans which is concerned with behavioural activities - It is the window through which limbic system sees the place of person in the worldQ Stimulation can cause all the effects of hypothalmus puls tonic / clonic / rhythmical / circling movements, rage, escape, punishment, severe pain, fear, reward, pleasure, and even sexual activities such as erection, copulatory movements, ejaculation, ovulation, uterine activity & premature labor. Kluver Bucy syndrome d/t bilateral ablation of arnygadalaQ presents with (1) loss of fear, (2) extreme curosity (3) tendency to place everything in mouth (4) forgets rapidly and (5) strong sex drive so much so that it attempts to copulate even with wrong (immature, wrong sex, different species) anmials & inanimate objects. Limbic coex Anterior temporal coex : Gustatory & olfactory behavioural association - Posterior orbital frontal coex damage: Insomnia with intense motor restlessness (unable to sit still & moving about continuously) Parahippocampal gyri : complex auditory & thought associations derived fro Wernike's area
Emotion
Memory
Higher function
All