Startle response
The startle response is a brainstem reflex that serves to protect the back of the neck (whole-body startle), or the eye (eyeblink), and also facilitates escape from sudden stimuli. It is found across the lifespan and in many species. An individual's emotional state may lead to a variety of different responses. The Startle Response is also known as the Moro Reflex in younger children and is said the change around 3-6 months.[1][2]
Acoustic Startle Reflex
The pathway for this response was largely elucidated in rats in the 1980s.[3]
In summary the basic pathway follows the auditory pathway from the ear up to the Nucleus of the Lateral Lemniscus (LLN) from where it then activates a motor centre in the reticular formation. This centre sends descending projections to lower motor neurones of the limbs. In slightly more detail this corresponds to: Ear (cochlea)->Cranial Nerve VIII (auditory) -> Cochlear Nucleus (ventral/inferior) -> LLN -> Caudal pontine reticular nucleus (PnC). The whole process has a less than 10ms latency. There is no involvement of the superior/rostral or inferior/caudal colliculus in the reaction that "twitches" the hindlimbs, but these may be important for adjustment of pinnae, gaze towards the direction of the sound or the associated blink.[4]
See also
- Prepulse inhibition - attenuation of the startle response after a weaker preceding stimulus, or prepulse.
- Surprise (emotion)
References
- ^ "Peter J. Lang,Margaret M. Bradley, Bruce M Cuthbert. "Emotion,attention, and the startle reflex" 1990". Mendeley.com. Retrieved 2011-10-01.
- ^ "Kendra Cherry "What is the Moro Reflex"". Psychology.about.com. 2011-03-21. Retrieved 2011-10-01.
- ^ Davis, M; Gendelman, Ds; Tischler, Md; Gendelman, Pm (1982). "A primary acoustic startle circuit: lesion and stimulation studies" (Free full text). Journal of Neuroscience. 2 (6): 791–805. ISSN 0270-6474. PMID 7086484.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - ^ Castellote, Jm; Kumru, H; Queralt, A; Valls-Solé, J (2007). "A startle speeds up the execution of externally guided saccades". Experimental brain research. Experimentelle Hirnforschung. Experimentation cerebrale. 177 (1): 129–36. doi:10.1007/s00221-006-0659-4. ISSN 0014-4819. PMID 16944110.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link)
External links
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