NAB-Fear and Anxiety

Fear and anxiety comprise protective/defensive responses normally elicited by aversive stimuli.
Much animal research on brain substrates of emotion over the last 30 years has focused on fear and anxiety.

Fear=phasic escape or avoidance responses to distinct aversive stimuli.
Anxiety=tonic response to diffuse aversive situations and is associated with conflict and uncertainty.

There are many types of fear and anxiety responses, the brain substrates of these different responses may differ.
Fear- and anxiety-related disorders in humans include generalised anxiety disorder, obsessive-compulsive disorder (OCD), panic disorder, phobias, and post-traumatic stress disorder(PTSD).

Amygdala

Lesions in amygdala affect the fear conditioning. Lateral and central amygdala having lesions would reduce fear response greatly.

The role of the amygdala in conditioned fear has been very well characterised, however other brain structures e.g. hippocampus, prefrontal cortex may also make important contributions to fear and anxiety, and the substrates of conditioned fear may differ from those of other fear/anxiety-related behaviours.
Amygdala is also involved in other emotional and behavioural processes.

Hippocampus

Hippocampal lesions increase the time rats spent in the open arms of the elevated plus-maze: hippocampal lesions reduce anxiety.

SO...

Is it necessary to refer to subjective feelings if we want to study brain substrates of emotions?
What advantages and disadvantages does it have to study neural mechanisms of emotion without reference to subjective feelings?
How can we study brain substrates relevant to fear/anxiety in rat models?
How can we confirm that similar brain substrates are also important for human fear/anxiety?

Emotional responses can be measured objectively, enabling the scientific study of emotions in animals.
In animal experiments, the measurement of emotional responses can be combined with a variety of techniques to manipulate and monitor brain function in order to reveal brain substrates of emotions and their dysfunctions.
The detailed information from animal experiments can be confirmed by appropriated research on human emotions in healthy subjects and clinical populations.

Of course, human emotions cannot be explained fully through animal studies; but a good understanding of some basic emotional mechanisms that are common to humans and other animals has already been formed.
The interaction between newly evolved functions i.e. language and consciousness, and emotions could be studied.