Title & Introduction
Page 1
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Offense, Defense & Patrol/Marking
Page 2
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Neural Circuitry & Motivational Mechanisms
Page 3
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How Circulating Hormones May Affect Behavior
Page 4
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Pregnancy and Lactation
Page 7
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ACTH, etc.
Page 8
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Reproductive States
Page 9
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Conclusion
Page 10
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References
Page 11
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HOW CIRCULATING HORMONES MAY AFFECT AGONISTIC BEHAVIOR
A schematic view of the neural circuitry of agonistic behavior in muroid rodents is shown in Figure 1. In the schema one can distinguish four motivational systems: patrol/marking, offense, submission, and defense. Each motivational system is divided into four components: sensory analyzers and synthesizers for motivating stimuli, motivational mechanism, motor patterning mechanisms, and sensory analyzers and synthesizers for releasing and directing stimuli. It may be seen that there may be considerable overlap and interrelationship among the various components and motivational systems. Most types of motivating and releasing and directing stimuli may affect more than one motivational mechanism, and most motor-patterning mechanisms may be activated by more than one motivational mechanism.
Although the schema may give the impression that the agonistic behavior of muroid rodents is "hard-wired" and inborn, it has been pointed out elsewhere that there are many ways in which it is modified and developed as a function of experience (Adams, 1979b, 1980). In fact, as will be documented below, hormonal effects are among the important ways that the systems are modified as a function of experience.
The schema enables one to make specific hypotheses about hormonal effects. First, which motivational system or systems does it affect? Does it affect patrol/ marking, offense, defense, or submission? And if it affects the latter two systems, does it act directly on the consociate modulator that switches the animal from defense to submission? Second, which component of a motivational system does it affect? Does it affect the motivational mechanism itself, the motor-patterning mechanism, or a particular sensory analyzer or synthesizer?
Ultimately, the answers to these questions will require appropriate single-neuron recording techniques, but in the meantime, tentative answers may be obtained from careful behavioral analysis.
To distinguish which motivational systems are influenced by a specific hormone, it is possible to rely on certain motor patterns that are characteristic of a particular system. Certain ambivalent motor patterns such as approach locomotion and sideways or upright postures are not specific enough for this method. Others, however, are not ambivalent and reflect the activation of one particular motivational mechanism. Thus, most of the scent-marking patterns are specific to patrol/marking, the bite-and-kick attack is specific to offense, the lunge-and- bite attack is specific to defense, and the full submissive posture may be specific to submission.
To distinguish which component of a motivational system is influenced by a specific hormone, it is necessary to test for a number of different motor patterns under a number of conditions involving different motivating stimuli. If the hormone acts on an analyzer or synthesizer of motivating stimuli, it will affect only the behaviors elicited by those motivating stimuli and not others. If it acts on the motivational mechanism, the hormone will affect the frequencies of all motor patterns in response to all types of conditions involving all of the various motivating stimuli. If it acts on a sensory analyzer for releasing and directing stimuli, or on a motor-patterning mechanism, it will affect only the particular motor pattern in question and not the other motor patterns activated by the same motivational system.
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