Karen  P.  Maruska

Associate Professor
CDIB and SEE Divisions

PhD: University of Hawaii, 2007

Phone: 225-578-1738

Lab Phone: 225-578-8057

E-mail: kmaruska@lsu.edu
Office: A345 Life Science Annex
Lab: A351/A349 annex and 378 LSB
Website:  Maruska Lab

Area of Interest

How does the nervous system integrate internal physiological cues with external biologically relevant stimuli, and then translate this information into adaptive behaviors?  My laboratory’s research is broadly focused on understanding the neural and molecular basis of natural social behaviors, including aggression and reproduction, and the mechanisms that underlie sensory, behavioral and neural plasticity. Investigating these mechanisms can reveal sensory, motor, and cognitive substrates on which selection can act to ultimately shape the evolution of organisms.

Our model organisms are fishes, the largest and most diverse group of vertebrates, because they provide ideal models to address questions on neuron function and how it relates to proximate and ultimate behavioral mechanisms in both comparative and evolutionary contexts.  We use a combination of approaches, including behavioral experiments, morphology, neuroanatomy and tracing studies, electrophysiology, immunohistochemistry, and gene expression analyses, to address specific hypotheses on how the nervous system controls diverse behaviors, and how brain function can be influenced by an animal’s own internal physiological and hormonal state.  We also address questions at multiple levels of biological organization, from whole organism behavior to cellular and molecular mechanisms. Specific areas of focus include multimodal (acoustic, chemosensory, mechanosensory, visual) communication and processing, the role of neuropeptides and sex-steroids as modulators of sensory system function, and the impact of social interactions on the brain and behavior.  

Students in the lab are encouraged to pursue their own hypothesis-driven research questions within the general focus of my research program, and to use a multidisciplinary approach to answer these questions

Selected Publications

Maruska, K.P., Zhang, A., Neboori, A., and R.D. Fernald. 2013. Social opportunity causes rapid transcriptional changes in the social behavior network of the brain in an African cichlid fish. J Neuroendocrinol. 25: 145-157.

Maruska, K.P., Carpenter, R.E. and R.D. Fernald. 2012. Social status regulates cell proliferation in the brain of the African cichlid fish Astatotilapia burtoni. J Comp Neurol 520: 3471-3491.

Fernald, R.D. and K.P. Maruska.  2012. Social information changes the brain. Proc Nat Acad Sci 109: 17194-17199.

Maruska, K.P., Ung, U., and R.D. Fernald.  2012. The African cichlid fish Astatotilapia burtoni uses acoustic communication for reproduction: sound production, hearing, and behavioral significance. PLoS One 7(5): e37612.

Maruska, K.P. and R.D. Fernald. 2012. Contextual chemosensory urine signaling in an African cichlid fish. J Exp Biol 215: 68-74.

Kustan, J.M., Maruska, K.P. and R.D. Fernald. 2012.  Subordinate male cichlids retain reproductive competence during social suppression. Proc Roy Soc B 279: 434-443 (with cover).

Maruska, K.P. and T.C. Tricas.  2011. Gonadotropin-releasing hormone (GnRH) modulates auditory processing in the fish brain. Horm Behav 59: 451-464 (with cover; Editor’s choice article).

Maruska, K.P., Levavi-Sivan, B., Biran, J. and R.D. Fernald.  2011. Plasticity of the reproductive axis during social ascent in an African cichlid fish: I – pituitary gonadotropins. Endocrinology 152: 281-290.

Grone, B.P., Maruska, K.P., Korzan, W.J. and R.D. Fernald.  2010. Expression pattern and social regulation of kisspeptin receptor in Astatotilapia burtoni.  Gen Comp Endocrinol 169: 98-107.

Maruska, K.P. and R.D. Fernald. 2010.  Steroid receptor expression in the fish inner ear varies with sex, social status, and reproductive condition.  BMC Neurosci 11:58.

Maruska, K.P. and R.D. Fernald.  2010. Behavioral and physiological plasticity: rapid changes during social ascent in an African cichlid fish. Horm Behav 58: 230-240 (with cover).

Maruska, K.P. and A.F. Mensinger.  2009. Acoustic characteristics and variations in grunt vocalizations in the oyster toadfish, Opsanus tau. Environ Biol Fish. 84: 325-337.

Maruska, K.P. and T.C. Tricas. 2009. Central projections of octavolateralis nerves in the brain of a soniferous damselfish (Abudefduf abdominalis). J Comp Neurol. 512: 628-650.

Dewan, A.K., Maruska, K.P. and T.C. Tricas.  2008. Arginine vasotocin neuronal phenotypes among congeneric territorial and shoaling reef butterflyfishes: Species, sex and reproductive season comparisons. J. Neuroendocrinol. 20: 1382-1394.

Maruska, K.P., Boyle, K.S., Dewan, L.R. and T.C. Tricas.  2007. Sound production and spectral hearing sensitivity in the Hawaiian sergeant damselfish, Abudefduf abdominalis. J Exp Biol. 210: 3990-4004 (with cover).

Maruska, K.P. and T.C. Tricas.  2007.  Gonadotropin-releasing hormone (GnRH) and receptor distributions in retinal and central visual processing regions of coral reef fishes.  Brain Behav. Evol. 70: 40-56 (with cover).

Maruska, K.P. and T.C. Tricas. 2004. Test of the mechanotactile hypothesis: neuromast morphology and response dynamics of mechanosensory lateral line primary afferents in the stingray. J. Exp. Biol. 207: 3463-3476 (with cover).

Maruska, K.P.  2001. Morphology of the mechanosensory lateral line system in elasmobranch fishes: ecological and behavioral considerations.  Environ. Biol. Fish.  60: 47-75.

Forlano, P.M., Maruska, K.P., King, J.A., Sower, S.A. and T.C. Tricas.  2000.  Differential distribution of GnRH-ir neurons in the stingray brain: functional and evolutionary considerations.  Gen. Comp. Endocrinol.  118: 226-248.

Maruska, K.P. and T.C. Tricas.  1998.  Morphology of the mechanosensory lateral line system in the Atlantic stingray, Dasyatis sabina: the mechanotactile hypothesis.  J. Morph.  238:1-22.