Cortical Structures of the Limbic System

Most notable structures Primary functionOrbitofrontal gyri Very diverseCingulate gyrus EmotionIsthmus Emotion + MemoryParahippocampal gyrus Memory Uncus Olfaction

Subcortical Structures of the Limbic System

Most notable structures:Septal nucleiNucleus accumbensMammillary bodyAmygdalaDorsal thalamusHabenulaHippocampal formation

Most notable efferent pathways:FornixStria terminalisVentral amygdalofugalMammilothalamic

Hippocampal Formation

Afferent PathwaysPerforant

AlvearFornix

Efferent PathwaysFornix

Amygdaloid Complex

Afferent PathwaysCingulum

Stria TerminalisLateral oflactory stria

Efferent PathwaysStria TerminalisAmygdalofugal

Septal Nuclei & Nucleus Accumbens

Septal PathwaysMFB (A&E)

Stria terminalis (A)Fornix (A&E)

Stria medullaris (E)

Nuc. Acc. PathwaysMFB (A&E)

Stria terminals (A)Fornix (A)

Learning and Memory

Associative Learning Formation of associations between 2 features in the environment

Nonassociative LearningExperience produces changes in the magnitude of the response

Hebb’s Postulate:

Cells that fire togetherwire together; Cells thatfire out of sync lose theirlink

Cellular Mechanisms of Memory

Long-Term Potentiation Enhancement of synaptic efficacy following strong stimulation