BI407 - Sensory Modalities and the Neuroendocrine Basis of Animal Behavior

umwelt

the sensory world is unique to each organism, shaped by its evolved sensory modalities and ecological needs

sensory bias

behaviors shaped by pre-existing preferences in perception

sensory exploitation

signals evolve to trigger those biases

reflex arc

somatic receptors to afferent nerve fibers to integrating center to efferent nerve fibers to skeletal muscles

core functions of the nervous system

transduction, coding, integration, motor output

transduction

converting environmental stimuli into electrical signals

coding

representing information via neuronal firing patterns

integration

combining sensory input with memory, motivation, and internal state

motor output

activating muscles or glands to produce behavior

chemoreception

taste, smell

photoreception

vision, UV/IR

mechanoreception

touch, sound, vibration

electroreception

electric fields

magnetoreception

Earth’s magnetic field

thermoreception

heat and cold, includes infrared detection

olfaction

detects airborne chemicals

gustation

detects chemicals in solutions

variation in visual systems includes

number and type of opsins, sensitivity to different wavelengths, spatial resolution, color discrimination

physical displacement

sound waves, substrate vibrations, direct touch or pressure

mechanoreceptors used for

prey detection, predator avoidance, communication, nativation

sensory structures specialized for air

tympanal membranes

sensory structures specialized for water

lateral line systems

sensory structures specialized for substrate

vibration-sensitive hairs or organs

auditory frequency ranges across species variation for

communication needs, predation and predator avoidance, habitat

hormones and neurochemicals shape

sensory processing and behavioral responsiveness

organizational effects of hormones

occur during early development and produce permanent structural changes in the brain and body

activational effects of hormones

occur in adulthood, often in response to environmental cues and are reversible and modify the activity of existing circuits

seasonal environmental changes

animals adjusting behavior in times

photoperiod

day length, reliable cue for timing behaviors