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# LABORATORY OF DEFENSIVE CONDITIONED REFLEXES

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# Head:

Tomasz WERKA, Ph.D., D.Sc.

E-mail: t.werka@nencki.gov.pl

Staff:

Janusz W. BŁASZCZYK, Ph.D., D.Sc., Joanna SADOWSKA, M.Sc.,

Grażyna WALASEK, Ph.D.,

Małgorzata WĘSIERSKA, Ph.D.,

Prof. Kazimierz ZIELIŃSKI, Ph.D., D.Sc.

Wojciech BORKOWSKI

Ph.D. Students:

Ewelina KNAPSKA, M.Sc.,

Paweł KUŚMIEREK, M.Sc.

The Laboratory of Defensive Conditioned Reflexes was created by Professor Kazimierz Zieliński, one of the most prominent Polish scientists in the area of neurophysiology of learning and defensive behavior. General line of research that was introduced by Professor Zieliński has still been continued by his students. Thus, strategies of learning, behavioral mechanisms of defensive and alimentary conditioning, processes of spatial, recognition and emotional memory, as well as their neural substrates are investigated. Moreover, the role of phylogenetic and ontogenetic factors in the emotional behavior is examined. Scientists that are assembled in the Laboratory are widely experienced in various behavioral techniques performed in several species of laboratory animals, including mice, rats, opossums, cats, dogs and monkeys. The advanced behavioral studies are combined with the molecular, pharmacological, neuroanatomical and lesion techniques.

The current research activity of the Laboratory covers the following three areas. The first one is devoted mostly to explore neuronal and molecular processes that are implicated in the defensive behavior. Experimental techniques used in the research include various behavioral tests (plus-maze, open-field, ASR as well as the shuttle-box avoidance, CER and Skinner-box procedures). Moreover, electrolytic and neurotoxic lesions, c-Fos and Zif268 immunocytochemistry, and APV infusion are employed. The investigations are focused on the cognitive and emotional mechanisms of Pavlovian and instrumental defensive conditioning, on interactions that exist between the emotional state and learning ability, as well as between states of anxiety and safety, between passive and active coping strategies and their endocrine correlates. Furthermore, functions of the limbic structures with special emphasis on the functional organization of the amygdaloid complex are investigated in a collaboration with the Laboratory of Molecular Neurobiology. The results obtained in the Laboratory indicate that the amygdala is not only important for the regulation of internal emotional states that motivate behavioral expression of those states, but it is also involved in cognitive evaluation of the environmental stimuli. The basolateral group of nuclei processes several subtle features of the conditioned stimulus (CS), and controls subject’s attention to modality, saliency and temporal attributes of the external cues. The central nucleus of the amygdala and dorsal part of the medial nucleus are involved mostly in evaluation of the aversive unconditioned stimuli (US). Moreover, these nuclei control mechanisms of fear transfer to newly introduced CS and US. Recently, the role of striatal structures in processing of motivational and signaling properties of environmental stimuli has been also examined.

The neurophysiology of cognition in spatial and recognition memory is the second topic of the Laboratory research. Experimental techniques include the test of place avoidance navigation, developed by J. Bureš and A.A. Fenton. The TTX and/or CNQX drugs are used to temporarily inactivate the hippocampus. Navigation based on external, distant visual cues (allothetic), defined by room-frame coordinates is distinct from navigation based on internal self-motion signals. Those internal cues are supported by external local cues, such as objects, tactile or olfactory marks (idiothetic cues) defined in arena-frame coordinates. The result demonstrates that place navigation consists of distinct allothetic and idiothetic navigations, and both these processes are simultaneously expressed in the environment. Most of the hippocampus is involved in coordination of the allothetic and idiothetic memory. However, even in the case of the hippocampus dysfunction rats are able to navigate in darkness. Dr. Danuta Kowalska initiated the study of neural basis of auditory recognition memory and auditory processing in dogs. This research has been continued despite Dr. Kowalska passed away in 2002. The Laboratory of Neuroanatomy identifies brain structures that may be involved in these processes, and effects of lesions to these structures upon performance on variety of behavioral tasks are investigated. The tasks include auditory Delayed Matching-to-Sample with trial-unique stimuli and an assortment of differentiation methods, which allow studying perception of distinct acoustical parameters. Results of these studies show that neither the hippocampus nor perirhinal nor entorhinal cortex participates in auditory recognition memory, contrary to visual, olfactory and tactual memory. A functional dissociation of two anatomical streams of cortical processing has been demonstrated. It is hypothesized that the ventral stream is involved in decoding qualitative properties of sound, such as timbre. The experiments are conducted in cooperation with the Laboratory of Neuroanatomy of the Nencki Institute, as well as with the National Institute of Mental Health, Georgetown University, University of Toronto, and University of Bristol.

The third area of researches concerns a significance of the phylogenetic, ontogenetic, and developmental factors on the cognitive and emotional behavior. It includes comparative behavioral studies on representatives of different animal species. Experiments are conducted with application of the spatial and novelty recognition setup, the open-field, ASR and CER tests, as well as the fear potentiated startle and shuttle-box procedures. Changes in learning and long-term memory of genetically engineered mice with disrupted or altered neural plasticity are also evaluated using various behavioral tests. Experimental models of the fear-potentiated startle and of the prepulse inhibition are employed in mice that have been selectively bred for high analgesia (HA) and low analgesia (LA). The results show that ASR magnitude is higher in the animals bred for high analgesia than in subjects bred for low analgesia. Moreover, HA animals display higher anxiety than LA subjects in the open-field test.

Selected publications:

1. Błaszczyk JW, Tajchert K, Werka T. (1999). Effect of nonaversive and aversive stimulations in infancy on the acoustic startle response in adult rats. Acta Neurobiol. Exp. 59:9-14.

2. Błaszczyk JW, Tajchert K, Lapo I, Sadowski B. (2000). Acoustic startle and open field behavior in mice bred for magnitude of swim analgesia. Physiol. Behav. 70:471-476.

3. Cimadevilla JM, Wesierska M, Fenton AA, Bures J. (2002). Inactivation one hippocampus impairs avoidance of a stable room-defined place during dissociation of arena cues from room cues by rotation of the arena. Proc. Natl. Acad. Sci. USA. 98:3531-3536.

4. Fenton AA, Bures J, Cimadevilla JM, Olypher AV, Wesierska M, Zinyuk L. Hippocampal place cell activity during overtly purposeful behavior (in dissociated reference frames) (2002). In: The neural basis of navigation. Evidence from single cell recording (Ed. P E Sharp). Kluwer Academic Publishers, 1-247.

5. Kowalska D.M., Kusmierek P., Kosmal A., and Mishkin M. (2001). Neither perirhinal/entorhinal nor hippocampal lesions impair short-term auditory recognition memory in dogs. Neuroscience 104:965-978.

6. Radwańska K., Nikolaev E., Knapska E., Kaczmarek L. (2002). Differential response of two subdivisions of the lateral amygdala to aversive conditioning as revealed by c-Fos and P-ERK mapping. Neuroreport, 13:2241-2246.

7. Savonenko A, Filipkowski RK, Werka T, Zielinski K, Kaczmarek L. (1999). Defensive conditioning-related functional heterogeneity among nuclei of the rat amygdala revealed by c-Fos mapping. Neuroscience 94:723-733.

8. Walasek G, Węsierska M, Werka T. (2002). Effects of social rearing conditions on conditioned suppression in rats. Acta Neurobiol. Exp. 62:25-31.

9. Wan H., Warburton E.C., Kusmierek P., Aggleton J.P., Kowalska D.M., and Brown M.W. (2001). Fos imaging reveals differential neuronal activation of areas of rat temporal cortex by novel and familiar sounds. European Journal of Neuroscience, 14(1): 118-124.

10. Werka T. (1998). Involvement of the lateral and dorsolateral amygdala in conditioned stimulus modality dependent two-way avoidance performance in rats. Acta Neurobiol. Exp. 58: 131-147.

11. Werka T, Zielinski K.(1998). CS modality transfer of two-way avoidance in rats with central and basolateral amygdala lesions. Behav. Brain Res. 93:11-24.

12. Wesierska M, Turlejski K.(2000). Spontaneous behavior of gray short-tailed opossum (Monodelphis domestica) in the elevated plus-maze: comparison with Long-Evans rats. Acta Neurobiol. Exp. 60:479-487.

13. Zielinski K, Savonenko AV. (2000). Escape from shock versus escape from shock accompanied by a visual stimulus in rats. Acta Neurobiol. Exp. 60:457-465.