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. and J.M. Butler. 2021. Reproductive- and social-state plasticity of multiple sensory systems in a cichlid fish. Integrative and Comparative Biology. 61: 249-268.

Grone, B.P., Butler, J.M., Wayne, C.R., and K.P. Maruska. 2021. Expression patterns and evolution of urocortin and corticotropin-releasing hormone genes in a cichlid fish. J Comp Neurol. 529: 2596-2619.

Butler, J.M., Herath, E., Rimal, A., Whitlow, S.M. and K.P. Maruska. 2020. Galanin activation in feeding, parental care, and infanticide in a mouthbrooding African cichlid fish. Horm. Behav. 126: 104870.

Butler, J.M. and K.P. Maruska. 2020. Noise during mouthbrooding impairs maternal care behaviors and juvenile development and alters brain transcriptomes in the African cichlid fish Astatotilapia burtoni. Genes, Brain and Behavior. 2020: e12692.

Maruska, K.P., Butler, J.M., Anselmo, C.A., and Tandukar, G. 2020. Distribution of Aromatase in the Brain of the African Cichlid Fish Astatotilapia burtoni: Aromatase Expression, But Not Estrogen Receptors, Varies with Female Reproductive-State. J Comp Neurol. 528: 2499-2522.

Butler, J.M., Whitlow, S.M., Rogers, L.S., Putland, R.L., Mensinger, A.F. and K.P. Maruska. 2019. Reproductive-state plasticity in the visual system of an African cichlid fish. Hormones and Behavior. 114: 104539.

Nikonov, A.A. and K.P. Maruska 2019. Male dominance status regulates odorant-evoked processing in the forebrain of a cichlid fish. Sci. Reports. 9:5083.

Field, K.E., McVicker, C.M., and K.P. Maruska. 2018. Sexually-relevant visual and chemosensory signals induce distinct behaviors and neural activation patterns in the social African cichlid, Astatotilapia burtoni. Front Behav Neurosci. 12: 267.

Butler, J.M., Whitlow, S.M., Roberts, D.A., and K.P. Maruska. 2018. Neural and behavioral correlates of repeated social defeat. Sci. Reports 8:6818.

Field, K.E. and K.P. Maruska. 2017. Context-dependent chemosensory signaling, aggression, and neural activation patterns in reproductively-receptive female African cichlids. J Exp Biol.220: 4689-4702.

Butler, J.M. and K.P. Maruska. 2016. The mechanosensory lateral line system mediates activation of socially-relevantbrain regions during territorial interactions. Front BehavNeurosci 10:93. 

Grone, B.P. and K.P. Maruska. 2015. A Second Corticotropin-Releasing Hormone Gene (CRH2) is Conserved Across Vertebrate Classes and Expressed in the Hindbrain of a Basal Neopterygian Fish, the Spotted Gar (Lepisosteus oculatus). J Comp Neurol. 523: 1125-1143.

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., 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.