Interpeduncular nucleus

The interpeduncular nucleus (IPN) is an unpaired, ovoid group of neurons at the base of the midbrain tegmentum.[1] The region is divided into 7 paired and unpaired subnuclei The presence of non-homologous subdivisions of the Interpeduncular nucleus was first noticed by Cajal over a hundred years ago.This pathway presents the IPN with several excitatory neurotransmitters including ACh and Substance P. Other brain regions that project to the Interpeduncular nucleus include: the Nucleus of diagonal band, the dorsal Tegmentum, the Raphe nuclei, the Central grey, and the Locus coeruleus.[4] The major output pathways are inhibitory and project to the dorsal Tegmental area, the Periaqueductal gray and also the Raphe nuclei.In addition, output is sent to the following: the mediodorsal nucleus of the Thalamus, the lateral Habenula, the Septal nuclei, the anterior Mammillary nuclei, the Nucleus of diagonal band, the Preoptic area, the Ventral tegmental area, and in some species the dorsal and/or lateral Hypothalamus.
NeuroNamesNeuroLexAnatomical terms of neuroanatomyneuronsmidbrain tegmentummidbraininterpeduncular fossacerebral pedunclesGABAergicmedial habenulaSubstance PNucleus of diagonal bandTegmentumRaphe nucleiCentral greyLocus coeruleusPeriaqueductal grayThalamuslateral HabenulaSeptal nucleiMammillary nucleiPreoptic areaVentral tegmental areaHypothalamusRapid eye movement sleepRegions in the human brainTectumCorpora quadrigeminaInferior colliculusSuperior colliculusGrey matterPretectal areaWhite matterSpinotectal tractCentral tegmental tractTectospinal tractCerebral aqueductPeduncleMedialLateralAscending MLFVestibulo-oculomotor fibersSpinothalamic tractVentral trigeminal tractDentatothalamic tractRubrospinal tractRubro-olivary tractDescending MLFcranial nucleiMesencephalicOculomotor nucleusTrochlear nucleusEdinger–Westphal nucleusRostromedial tegmental nucleusRed nucleusRostral interstitial nucleus of medial longitudinal fasciculusParabrachial areaMidbrain reticular formationDorsal tegmental nucleusdorsalReticulotegmental nucleusCerebral crusPyramidal tractsCorticospinal tractCorticobulbar tractCorticopontine tractFrontopontine fibersTemporopontine fibersSubstantia nigraPars compactaPars reticulataSuperior cerebellar peduncleDecussation