Biomedical subjects

Jessica Porter

Publications and source records attributed to Jessica Porter.

3 recordsLinked to original sources

PubMed2005

Nicotine enhances both foreground and background contextual fear conditioning.

The present study examined if nicotine enhances contextual fear conditioning when the training context is either a background stimulus or a foreground stimulus. In the background conditioning experiment, mice were trained using two auditory conditioned stimulus (CS; 30 s, 85 dB white noise)-footshock unconditioned stimulus (US; 2 s, 0.57 mA) pairings and tested 24 h later. In the foreground conditioning experiment, mice were trained with two presentations of a footshock US (2 s, 0.57 mA) and tested 24 h later. Mice received 0.09 mg/kg nicotine before training and testing. For both the foreground and background conditioning experiments, nicotine enhanced contextual conditioning. No enhancement of the auditory CS-US association was seen. These results demonstrate that nicotine enhances contextual fear conditioning regardless of whether the context is a background stimulus or a foreground stimulus during conditioning.

Acoustic Stimulation↗

PubMed2004

Myo1c is designed for the adaptation response in the inner ear.

The molecular motor, Myo1c, a member of the myosin family, is widely expressed in vertebrate tissues. Its presence at strategic places in the stereocilia of the hair cells in the inner ear and studies using transgenic mice expressing a mutant Myo1c that can be selectively inhibited implicate it as the mediator of slow adaptation of mechanoelectrical transduction, which is required for balance. Here, we have studied the structural, mechanical and biochemical properties of Myo1c to gain an insight into how this molecular motor works. Our results support a model in which Myo1c possesses a strain-sensing ADP-release mechanism, which allows it to adapt to mechanical load.

Adaptation, Biological↗

PubMed2003

Olfactomotor activity during imagery mimics that during perception.

Neural representations created in the absence of external sensory stimuli are referred to as imagery, and such representations may be augmented by reenactment of sensorimotor processes. We measured nasal airflow in human subjects while they imagined sights, sounds and smells, and only during olfactory imagery did subjects spontaneously enact the motor component of olfaction--that is, they sniffed. Moreover, as in perception, imagery of pleasant odors involved larger sniffs than imagery of unpleasant odors, suggesting that the act of sniffing has a functional role in creating of olfactory percepts.

Auditory Perception↗