The nucleus incertus is a region of the pontine brainstem just ventral to the 4th ventricle.[1] The term was coined by George Streeter (Latin for "uncertain nucleus") based on its unknown function at the time, to name a group of cells he observed near the midline of the floor of the 4th ventricle.[2] It sometimes called the 'nucleus O'.[3]
It is part of the theta network acting as a relay from the reticularis pontis oralis nucleus to the septo-hippocampal system.[6] The stimulation of the nucleus incertus activates the hippocampal theta rhythm and either its lesion or inhibition suppress the theta oscillation induced by brainstem stimulation.[7] The nucleus incertus itself presents theta oscillations coupled to the hippocampal theta rhythm.[8]
In addition to hippocampal theta rhythms, the nucleus incertus is involved in the control of locomotor speed and arousal,[9]response to stress[3] and integrating the vestibulo-ocular reflex and gaze holding with hippocampal navigation.[6]
References
^Goto M, Swanson LW, Canteras NS (September 2001). "Connections of the nucleus incertus". The Journal of Comparative Neurology. 438 (1): 86–122. doi:10.1002/cne.1303. PMID11503154.
^Cervera-Ferri A, Rahmani Y, Martínez-Bellver S, Teruel-Martí V, Martínez-Ricós J (May 2012). "Glutamatergic projection from the nucleus incertus to the septohippocampal system". Neuroscience Letters. 517 (2): 71–6. doi:10.1016/j.neulet.2012.04.014. PMID22521581. S2CID32163510.
^ abTeruel-Martí V, Cervera-Ferri A, Nuñez A, Valverde-Navarro AA, Olucha-Bordonau FE, Ruiz-Torner A (July 2008). "Anatomical evidence for a ponto-septal pathway via the nucleus incertus in the rat". Brain Research. 1218: 87–96. doi:10.1016/j.brainres.2008.04.022. PMID18514169. S2CID5519042.
^Nuñez A, Cervera-Ferri A, Olucha-Bordonau F, Ruiz-Torner A, Teruel V (May 2006). "Nucleus incertus contribution to hippocampal theta rhythm generation". The European Journal of Neuroscience. 23 (10): 2731–8. doi:10.1111/j.1460-9568.2006.04797.x. PMID16817876.
^Cervera-Ferri A, Guerrero-Martínez J, Bataller-Mompeán M, Taberner-Cortes A, Martínez-Ricós J, Ruiz-Torner A, Teruel-Martí V (June 2011). "Theta synchronization between the hippocampus and the nucleus incertus in urethane-anesthetized rats". Experimental Brain Research. 211 (2): 177–92. doi:10.1007/s00221-011-2666-3. PMID21479657. S2CID23444954.