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INTERNATIONAL VOLUNTEER PROGRAM
APPLICATION FORM
Name, address and telephone number of the person responsible for this proposal
Prof. Frederic Libersat, Chairman, Dept of Life Sciences, Ben Gurion University, POB 653, Beer Sheva,
Israel 84105, Tel: + 972 86472112, Cell phone: + 972 (0)502029643, e-mail: [email protected]
Name of the laboratory and host institution
Laboratory of behavioral Neurobiology, Dept of Life Sciences, Ben Gurion University, POB 653, Beer Sheva,
Israel 84105
Title of the research project in which the volunteer would be involved
Cellular and molecular mechanisms of host behavior manipulation by a parasitoid wasp
Have you already identified a candidate?
Name and email address of the candidate:
NO
Background, knowledge and level required from the applicant volunteer (including languages)
Electrophysiology, immunohistochemistry, biochemistry techniques,
English
Suitable date for
receiving the volunteer
January 1, 2012
French Embassy in Israel
Office for Science & Technology
Rothschild Boulevard 7
Tel Aviv, 66881 Israel
Duration of the stay
Participation in the
monthly allowance
12 months
Tel: +972 (0)3 796 80 42
Fax: +972 (0)3 796 80 45
Web : http://www.fitscience.wordpress.com
Email : [email protected]
750 euros
Description of the specific research work, which would be carried out
Background
The parasitoid wasp Ampulex compressa delivers a sting precisely into the cerebral ganglia of its host, the
American cockroach. This sting does not kill or paralyze the cockroach but rather reduces its ability to
spontaneously generate movements. So far, our investigation of this unique behavioral manipulation revealed
a possible neuronal substrate involved in the regulation of behavioral choice and spontaneity in insects. In the
present proposal our goal is to identify the molecular and cellular mechanisms underlying this venom-induced
manipulation.
To identify the cellular targets of the venom we will use a combination of electrophysiological methods
including field potential, tetrode, single microelectrode and amperometric recordings to identify the neuronal
circuits targeted by the venom.
To identify the molecular targets of the venom we will use two-dimensional (2D) electrophoresis (DIGE),
where multiple protein samples from the brains of stung and nonstung cockroaches will be labeled and the
proteins separated. The over- and under-expressed proteins in stung cockroaches will then be extracted and
their mass and amino acid sequence determined via mass-spectrophotometry and aligned against available
databases.
By studying the effect of the wasp’s venom on its cockroach host we hope to further our understanding of the
neuronal basis of parasite-induced alterations of host behavior and of the neurobiology of initiation of motor
behaviors in insects. The latter may have implications for our understanding of the control of locomotion by
higher neuronal centers in mammals, and for the use of insect models for mammalian neurological disorders.
Research objectives
In the present proposal, our main objective is to identify the molecular and cellular modifications occurring in
the host brain as a result of venom injection by the wasp.
Objective 1: Characterization of neuronal activity of SEG-DUM octopaminergic neurons during the execution
of motor behaviors in cockroaches, and further characterization of the role of octopamine in venom-induced
hypokinesia. The activity of identified SEG-DUM neurons will be recorded at rest, in response to specific
sensory stimuli and during different motor behaviors. Furthermore, the spontaneous and evoked release of
OA will be measured in the central part of the brain where OA neurons project.
Objective 2: Characterization of the neuronal activity of the Central Body Complex network in vivo in stung
and non-stung cockroaches.
Objective 3: Identification of possible molecular targets of the venom in the brain and SEG using differential
gel electrophoresis (DIGE).
Significance
Neurotoxins have proven to be invaluable as tools to reveal physiological mechanisms underlying nervous
system functions. Because neurotoxins are the outcome of one animal’s evolutionary strategy to incapacitate
another, they are usually highly effective and specific. Chemical engineers can generate hundreds of
French Embassy in Israel
Office for Science & Technology
Rothschild Boulevard 7
Tel Aviv, 66881 Israel
Tel: +972 (0)3 796 80 42
Fax: +972 (0)3 796 80 45
Web : http://www.fitscience.wordpress.com
Email : [email protected]
neurotoxins in their labs, but these products are random and often useless, whereas any natural neurotoxin
has already passed the ultimate screening test, over millions of years of co-evolution. For the past 10 years,
we have been working on deciphering the neurotoxic chemical manipulation of an animal by a unique
predator, the parasitoid wasp A. compressa (Libersat et al. 2009).
The differences between insects and mammals in brain structures and their effects on locomotion are, in
essence, more anatomical than functional (Strausfeld 1999). Brain areas controlling similar functions in
mammalian and insect brains may require similar connectivity, regulated by similar sets of genes (Strausfeld
1999). Thus, understanding of how locomotor activity is organized in the insect central nervous system, and
its corollary, the decision-making process, is bringing us closer to understanding how this activity is organized
in higher organisms including humans and other mammals. Moreover, since locomotion reflects a decision
making process, made according to the internal and external conditions of the animal, the decision to walk is
correlated with the motivational state or drive of the animal. The underpinnings of the various phenomena
comprising motivation, drive and spontaneity, in spite of their major significance in understanding the control
of initiation of locomotion, are still poorly understood. Our study of the venom-induced manipulation of
cockroach motor behavior could clearly aid such investigations.
Our research has been published as several invited reviews and incorporated as a classical case study in
numerous Neuroethology courses in several universities in the USA. It has become text book material
(Encyclopedia of Animal Behavior published by Elsevier). Our work has been also presented in the headlines
of the general press (Nature News, Science News, New Scientist, National Geographic, Scientific American,
Galileo, Pour la science and the like) and was the object of a special program on the Discovery Channel and
the History Channel. Our exploration has had an impact on Science education and public awareness of the
necessity for basic research. We are confident that the Cockroach Wasp will no doubt make public news in
years to come, because it has more to teach us.
To conclude, we hope that by investigating the neuronal basis of such parasite induced alterations of host
behavior we might further our understanding of the neurobiology of the selection and initiation of behaviors
and the associated neural mechanisms underlying changes in behavioral spontaneity.
References:
Gal R, Libersat F. (2008) A Parasitoid Wasp Manipulates the Drive for Walking of Its Cockroach Prey. Curr
Biol. 18(12):877-82.
Gal R, Libersat F. (2010) Wasp Manipulates Specific Neuronal Circuitry to Decrease the Drive for Walking in
its Cockroach Prey. PLoS One. 7;5(4):e10019.
Libersat F, Delago A and Gal R. (2009). Manipulation of host behavior by parasitic insects and insect
parasites. Annu Rev Entomol. 54:189-207
Frédéric Thomas et Frédéric Libersat. (2010) Pour la Science: Les parasites manipulateurs. Pour la Science n° 390 - Avril 2010; pages 2-8
French Embassy in Israel
Office for Science & Technology
Rothschild Boulevard 7
Tel Aviv, 66881 Israel
Tel: +972 (0)3 796 80 42
Fax: +972 (0)3 796 80 45
Web : http://www.fitscience.wordpress.com
Email : [email protected]