Behavioral Genetics and Animal Science - Genetics and the Behavior of Domestic Animals - page 16

This system promotes learning by urging animals to explore and to find
resources needed for survival. A dog that excitedly sniffs and explores every
room when turned loose in a strange house is an example of high SEEKING
in an animal.
LUST: The lust system in the brain controls sexual desire or appetite.
Sexual urges are mediated by specific brain circuits and chemistries that over-
lap but are distinct between males and females and are aroused by male and
female hormones.
CARE: The maternal nurturing system that assures that parents take care
of their offspring. Hormonal changes at the end of pregnancy activate maternal
urges that promote social bonding with the offspring.
PLAY: A key function of the play system is to help young animals acquire
social knowledge and refine subtle social interactions needed to thrive. One
motivation for PLAY is the dopamine energized SEEKING system.
The existence of these emotional structures is well documented and review
articles on this research can be found in Morris et al.(2011) , Burgdorf and
Panksepp (2006) ,and Panksepp (2011) . Direct electrical or chemical stimula-
tion of specific subcortical structures elicit emotional responses. The brain
circuits controlling fear and seeking have been extensively mapped ( LeDoux,
2000; Reynolds and Berridge, 2008 ).
Confusion of Emotional Systems May Confound Studies
In the behavior literature, many inconsistencies exist in papers on novelty
seeking and fear. Novelty seeking may be confused with other emotional
systems when terms such as activity level or emotional reactivity are used.
Confusion may also exist between FEAR and PANIC when the term reactivity
is used. The FEAR and PANIC (separation distress) systems have totally differ-
ent functions. Fear keeps an animal away from danger and the PANIC system
prevents the offspring from getting separated from its mother and helps to keep
social groups together. Some scientists assume that an open-field test only
evaluates fearfulness in animals (see Chapter 4). An animal alone in an
open field may be reacting to separation from its mother or the social group.
Confusing fear and separation distress is more likely when herding and flocking
animals are tested in an open field, compared to animals that live a more
solitary life. Panksepp's framework of the seven emotional systems may help
sort out conflicting results in the scientific literature.
Research by Reynolds and Berridge (2008) has shown that the emotional
traits of seeking novelty and fear are both controlled in a structure in the
brain called the nucleus accumbens. When one end of the nucleus accumbens
is stimulated, the animal becomes fearful. Stimulating the other end turns on
seeking ( Faure et al., 2008 ). There is a mixture of fear and seeking receptors
in the middle portion of the nucleus accumbens. The discovery of this function
for the nucleus accumbens may explain the “curiously afraid” behavior we