LABORATORY OF
LIMBIC SYSTEM
|
Head: Stefan KASICKI, Ph.D., D.Sc. E-mail: s.kasicki@nencki.gov.pl Staff: Paweł BOGUSZEWSKI, M.Sc. Anna KORZENIEWSKA-JANISZEWSKA, M.Sc., Krystyna MIŁOSZ Jolanta ZAGRODZKA, Ph.D., D.Sc. Ph.D. Students: Małgorzata BASZCZAK, M.Sc. Paweł BORATYŃSKI, M.Sc |
Laboratory of Limbic System was founded by Prof. Elżbieta Fonberg, prominent and
well-known scientist in the area of neurophysiology of emotions and motivation.
This line of research is still continued by Jolanta Zagrodzka and her collaborators. After a long period of
work on dogs and cats, currently various aspects of emotional behavior are
studied in rats, with the use of ethopharmacological
approach concomitantly with biochemical analysis and recording of local field
potentials. Pavlovian aversive conditioning and
autonomic correlates of behavior (heart rate and diaphragm EMG activity) are
used as well.
Recently the research
is focused mainly on the brain defensive system with special interest paid to
mechanisms of fear, anxiety and aggressive behavior. The series of experiments
was done on rats confronted with stressogenic stimuli
in order to determine the possible interactions between different neurotransmiters’ activity in correlation with
behavioral alterations (9-11). In other work it was found that experimentally
evoked affective states, i.e. fear, anxiety and
inhibition of fear elicit characteristic pattern of ultrasound vocalization
changes. Application of selected pharmacological agents allowed dissociating
their target of action as directed to the anxiety level or learned responses to
the stimuli of danger or safety (2).
Emotional changes
related to age are investigated in combined behavioral and biochemical study.
With the use of factor analysis motivational factors influencing spontaneous
behavior in open field, elevated plus maze and social interactions test were
identified in young and old animals. It has been demonstrated that, in addition
to the decrease of motor activity, old rats differ quantitatively and
qualitatively from young individuals in emotional and social behavior (1).
Currently, the electrophysiological correlates of the differences in emotional
reactivity between RHA and RLA rats are studied.
The second main topic
of the research in the laboratory was the movement control, started by Dr. Zofia Afelt and continued by Kasicki and his coworkers. It is well known that limbic and
motor systems are associated anatomically and functionally, and locomotion is a
major component of food procurement, escape and other motivational/adaptive
behaviors. One line of experiments was designed for analysis of theta rhythm recorded
in hippocampus and hypothalamic area during locomotion (7, 8). The conclusion
of the papers was that the theta rhythm frequency may depend not only on the
speed of locomotion but also on the rat’s motivational-emotional state,
associated with locomotion performed by the animal.
Affective processes
occurring in the limbic structures gain access to the motor structures,
initializing and shaping necessary action. The nucleus accumbens
is considered a nodal point, through which this access is performed. The
limbic-motor integration was studied by analysis of local field potentials
(LFP) recorded from n. accumbens, basolateral n.
of amygdala, ventral subiculum
and subpallidal area in freely moving rats, during locomotor tasks in various behavioral situations. Analysis
of partial coherences showed that the strength of connections between
structures is sensitive to changes in both motor and emotional aspects of
behavioral situation. (5). A new method (directed Direct Transfer Function)
enables obtaining the reliable pattern of connections between various brain
structures. The results demonstrate the effectiveness of the new dDTF method and indicate that the dDTF
method can be used to obtain patterns of information flow between investigated
structures (5, 6).
The
influence of emotional state on hippocampal LFP
activity is analyzed in another experimental paradigm, which enables studying
the fear and relief from it. Partially restrained rats, implanted with chronic
electrodes, are put to the Pavlovian aversive
conditioning procedure, during which the LFPs are
recorded. Preliminary results clearly demonstrate differentiation of hippocampal activity in opposite emotional states.
Recently
the scientific interests of the laboratory team have spread out – the neuronal
mechanisms of interactions between neurons are studied in electrophysiological
experiments on thalamo-cortical slices and in
modeling experiments. In in vitro experiments the organization of
mutual connections between neurons in layers V and VI of barrel cortex and
neurons in
Experiments
investigating various aspects of plasticity of motor system were performed in
collaboration with U. Sławińska (14, 15).
Analysis of activity of spinal neurons in the lamprey’s spinal cord was
done in collaboration with J. Buchanan (12, 13).
Selected
publications:
1. Boguszewski P, Zagrodzka J (2002)
Emotional changes related to age in rats - a behavioral analysis. Behav Brain Research 133(2):323-32.
2. Jelen P, Soltysik
S, Zagrodzka J. (2003) 22-kHz ultrasonic vocalization
as an index of anxiety but not fear: behavioral and pharmacological modulation
of affective state. Behav Brain Research
141(1):63-72.
3. Jelen P, Zagrodzka J (2001) Heart
rate changes in partially restrained rats during behaviorally and
pharmacologically evoked emotional states. Acta Neurobiol Exp 61(1):53-67.
4. Korzeniewska A, Kasicki S,
Kaminski M, Blinowska KJ (1997) Information flow between
hippocampus and related structures during various types of rat's behavior. J Neurosci Methods 73(1):49-60.
5. Korzeniewska A, Kasicki S, Zagrodzka J (1997) Electrophysiological correlates of the
limbic-motor interactions in various behavioral states in rats. Behav Brain Research 87(1):69-83.
6. Korzeniewska A, Mańczak M, Kamiński M, Blinowska KJ, Kasicki S (2003) Determination of information flow
direction among brain structures by a modified Directed Transfer Function (dDTF) method. J Neurosci Methods
125(1-2):195-207.
7. Slawinska U, Kasicki S (1995)
Theta-like rhythm in depth EEG activity of hypothalamic areas during
spontaneous or electrically induced locomotion in the rat. Brain Research
678(1-2):117-26.
8. Slawinska U, Kasicki S (1998) The frequency of rat's hippocampal
theta rhythm is related to the speed of locomotion. Brain Research
796(1-2):327-31.
9. Zagrodzka J (1995) Responsiveness to environmental stimuli
after destruction of the locus coeruleus
noradrenergic system. Human Psychopharmacology 10:467-73.
10. Zagrodzka J, Romaniuk A, Wieczorek M, Boguszewski P (2000)
Bicuculline administration into ventromedial
hypothalamus: effects on fear and regional brain monoamines and GABA
concentrations in rats. Acta Neurobiol
Exp 60(3):333-43.
11. Zagrodzka J, Wieczorek M, Romaniuk A (1994) Social interactions in rats: behavioral
and neurochemical alterations in DSP-4-treated rats.
Pharmacology, Biochemistry and Behavior 49(3):541-8.
Publications
in collaboration:
12.
Buchanan JT, Kasicki S (1999) Segmental distribution
of common synaptic inputs to spinal motoneurons
during fictive swimming in the lamprey. J Neurophysiology 82(3):1156-63.
13.
Buchanan JT, Kasicki S (1995) Activities of spinal
neurons during brain stem-dependent fictive swimming in lamprey. J
Neurophysiology 73(1):80-7.
14. Slawinska U, Kasicki S (2002)
Altered electromyographic activity pattern of rat soleus muscle transposed into the bed of antagonist muscle.
J Neuroscience 22(14):5808-12.
15. Slawinska U, Tyc F, Kasicki S, Navarrete R, Vrbova G (1998) Time course of changes in EMG activity of
fast muscles after partial denervation. Exp Brain
Research 120(2):193-201.