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 (
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,
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.