Research Assitant Professor of Psychology

Neuroscience

Office: 063 Wilson Hall
Phone: (615) 322-5263
Email:

Degrees

PhD. University of Warsaw, Poland, 1985

Research Area

Anatomical and functional organization of motor and sensory systems in primates

Current Research

Posterior parietal cortex and complex motor behavior. The goal of this project is to better understand involvement of posterior parietal cortex in motor behavior. The dominant view of function is that posterior parietal cortex uses visual, somatosensory, and auditory inputs to guide eye and limb movements in space. However, few subdivisions are well defined, and connection patterns are only broadly understood. We use intracortical microstimulation technique (motor mapping) to delivered trains of electrical pulses via microelectrodes to define and describe the major movement zones in posterior parietal cortex of anesthetized monkeys and galagos and study connections of these zones with other areas and subcortical nuclei, especially with premotor cortex. The results will provide new insights into the functional organization of posterior parietal cortex, and how functions are mediated via differing connection patterns, epecially with motor fields.
Distribution of sascending somatosensory pathways . The organization and connection patterns of two main ascending somatosensory pathways (dorsal column-medial lemniscus and spinothalamic tracts) that convey information from the skin, joints or muscles receptors to higher brain centers have not been fully understood. By injecting dorsal column nuclei and spinal cord with different tracers we study their projections to sensorimotor thalamus. Results will improve our understanding of the processing of somatosensory information, and the ways in which each of these main subcortical somatosensory structures interact with other somatosensory processing stations.
Anatomical substrates for movement controlThe major goal of the project is to understand the interface between the basal ganglia output nuclei and the cerebellum in the production of coordinated goal directed movements. The focus is on the sources of input to the different areas in the motor cortical region in primates using anatomical tract tracing methods.

Representative Publications

Stepniewska, I, Preuss, TM and J.H. Kaas (2005) Ipsilateral cortical connections of dorsal and ventral premotor areas in New World owl monkeys. J Comp Neurol. 495:691-708.
Stepniewska, I., Fang, P-C and J.H. Kaas (2005) Microstimulation reveals specialized subregions for different complex movements in the posterior parietal cortex of prosimian primates. PNAS 102:4878-4883.
Stepniewska, I.,Collins, C.E., and J.H. Kaas (2005) Reappraisal of DL/V4 boundaries based on connectivity patterns of dorsolatearl visual cortex in macaques. Cereb Cortex 15(6):809-22.
Stepniewska, I. (2004) The pulvinar complex. In: The primate visual system. CRC Press LLC. (Eds.) J.H. Kaas and C.E. Collins., pp.53-80.
Stepniewska, I., S.T. Sakai, H.X. Qi, and J.H. Kaas. (2003) Somatosensory input to the ventrolateral thalamic region (VL) in the macaque monkey: a potential substrate for parkinsonian tremor. J Comp Neurol 455:378-395
Kaas, J.H. and I. Stepniewska. (2002) Motor cortex. In: Encyclopedia of the human brain. Academic Press. (ed. V.S. Ramachandran)
Stepniewska, I., H-X. Qi, and J.H. Kaas. (2000). Projections of the superior colliculus to subdivisions of the inferior pulvinar in New World and Old World monkeys. Vis. Neurosci. 17:1-21.
Kaas, J.H. and I. Stepniewska (1999) Motor cortex. In: Wong-Riley, M.T.T. (ed.). Neuroscience secrets. Hanley & Belfus, Inc., Philadelphia, pp. 177-188.
Stepniewska, I., Qi, H-X., and J.H. Kaas (1998) Do superior colliculus projection zones in the inferior pulvinar project to MT in primates? Europ. J. Neurosci. 1: 101-112.
Stepniewska, I. and J.H. Kaas (1997) Architectonic subdivisions of the inferior pulvinar in Simian primates. Vis. Neurosci. 14:1043-1060.
Stepniewska, I. and J.H. Kaas (1996) Topographic patterns of V2 cortical connections in macaque monkeys. J. Comp. Neurol., 371:129-152.
Stepniewska, I., T.M. Preuss, and J.H. Kaas (1994) Thalamic connections of the primary motor cortex (M1) of owl monkeys. J. Comp. Neurol. 349:558-582.
Stepniewska, I., T.M. Preuss, and J.H. Kaas (1994) Architectonic subdivisions of the motor thalamus of owl monkeys: Nissl, acetylcholinesterase and cytochrome oxidase patterns. J. Comp. Neurol. 349:536-557.
Stepniewska, I., T.M. Preuss, and J.H. Kaas (1993) Architectonics, somatotopic organization and ipsilateral cortical connections of the primary motor area (M1) of owl monkeys. J. Comp. Neurol. 329:1-34.
Stepniewska, I. and G. Rajkowska (1989) Distribution of sensory projections in the frontal association cortex in the dog. Acta Neurobiol. Exp. 49: 299-310.
Stepniewska, I. and A. Kosmal (1986) Subcortical afferents to the mediodorsal thalamic nucleus of the dog. Acta Neurobiol. Exp. 46: 323-329.
Stepniewska, I. and A. Kosmal (1986) Distribution of mediodorsal thalamic nucleus afferents originating in the prefrontal association cortex of the dog. Acta Neurobiol. Exp. 46: 311-322.