Auditory startle

Rat, Rattus sp. 6.7 mg/kg body weight (BW) Single intraperitoneal (ip) injection caused deficits in auditory startle habituation tests 1... 

Conner, R. J., Stolk J. M., Barchas, J. D., and Levine, S. (1970) Parachlorophenylalanine and habituation to repetitive auditory startle stimuli in rats. Physiol. Behav., 5 1215-1219. 

Another test paradigm for detecting treatment effects on brain functioning in Fj offspring measures auditory startle habituation. In this test, the animal is placed in a chamber with a floor that detects movement. The animal is exposed to a sequence of 50 to 60 auditory stimuli, each at 110 to 120 decibels for 20 to50 sec and separated by 5 to 20 sec. The gradual diminution of the animal s movement response is indicative of normal habituation. 

Pinna reflex Preyer s reflex (auditory startle response) Pupillary reflex... 

Auditory Startle reflex Prepulse modulation Rat Colley et al.195... 

Pontieri FE, Tanda G, Orzi F, Di Chiara G (1996) Effects of nicotine on the nucleus accumbens and similarity to those of addictive drugs. Nature 382 255-257 Quik M (2004) Smoking, nicotine and Parkinson s disease. Trends Neurosci 27 561-568 Rasmussen K, Kallman MJ, Helton DR (1997) Serotonin-IA antagonists attenuate the effects of nicotine withdrawal on the auditory startle response. Synapse 27 145-152 Rice ME, Cragg SJ (2004) Nicotine amplifies reward-related dopamine signals in striatum. Nat Neurosci 7 583-584... 

HT1A antagonist Reversed withdrawal-induced increased in auditory startle Rasmussen et al. (2000)... 

Both chlorine dioxide and chlorite appear to induce delays in neurodevelopment, as evidenced by delayed brain growth, decreased locomotor and exploratory behavior, and altered auditory startle response in animals exposed during critical periods of neurodevelopment. It is not known whether similar chlorine dioxide- or chlorite-induced neurodevelopmental effects might occur in humans. 

Rat (Sprague- Dawley) 16 wk (W) 2. M 5.7 M lowered auditory startle response amplitude on postnatal day 24 Gill et al. 2000 Chlorite... 

ATSDR has derived an intermediate-duration oral MRL of 0.1 mg/kg/day for chlorite based on a NOAEL of 2.9 mg chlorite/kg/day and a LOAEL of 5.7 mg chlorite/kg/day for neurodevelopmental effects (lowered auditory startle amplitude) in rat pups that had been exposed throughout gestation and lactation via their mothers (Gill et al. 2000 same study as CMA 1996). The NOAEL of 2.9 mg chlorite/kg/day was divided by an uncertainty factor of 30 (10 for interspecies extrapolation and 3 to account for sensitive populations). 

Auditory startle. This test involves the response (movement) to a sound stimulus either without, or preceded by, a light-flash stimulus. 

Caffeine, which is present in coffee, tea, cocoa and cola, but also in various over-the-counter medications, has been shown to be clearly teratogenic in rats in doses comparable to those ingested daily by many people (refs. 30, 47, 55). Vest et al. (ref. 47) found that a dose as small as 5 mg/kg caffeine (comparable to the content of 4 cups of coffee) administered on gestational days 3-19 in the rat, affected not only physical development (e.g. delayed incisor eruption in males and females, vaginal opening in females, slower growing body weight) but also development of the auditory startle reflex, food and water intake, passive and active avoidance at adult age. 

Golub MS, Han B, Keen CL, et al. 1994. Auditory startle in Swiss Webster mice fed excess aluminum in diet. Neurotoxicol Teratol 16 423-425. 

General development—pinna unfolding (PND 1), surface righting (PND 4), hair growth (PND 7), incisor eruption (PND 7), eye opening (PND 11), and auditory startle (PND 21)... 

Kalinichev M, Holtzmann SG (2003) Changes in urina-tion/defecation, auditory startle response and startle-ultrasonic vocalizations in rats undergoing morphine... 

Prohaska JR, Hoffinan RG. Auditory startle response is diminished in rats after recovery from perinatal copper deficiency. J Nutr 1996 126 618-27. 

Rat GcslAlion d 6-9 (in No NOAEL 2 Increased auditory Startle response Buelke-Eam ot al. 

Neuromuscular and sensory effects were evaluated in Long Evans rats exposed to 500 ppm (6 hours a day for 5 or 12 weeks) using an acoustic startle test (Clerici and Fechter 1991). Neuromuscular integrity was shown to be compromised based on auditory startle reflex amplitude animals showed a 70% recovery 4 weeks postexposure. No clinical signs of neurotoxicity or changes in hearing function or acoustic tone thresholds were noted. Use of a single exposure concentration precluded assessment of dose response. 

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