Search results for " Eyelid"
showing 10 items of 25 documents
Hippocampal theta phase-contingent memory retrieval in delay and trace eyeblink conditioning
2017
Hippocampal theta oscillations (3-12Hz) play a prominent role in learning. It has been suggested that encoding and retrieval of memories are supported by different phases of the theta cycle. Our previous study on trace eyeblink conditioning in rabbits suggests that the timing of the conditioned stimulus (CS) in relation to theta phase affects encoding but not retrieval of the memory trace. Here, we directly tested the effects of hippocampal theta phase on memory retrieval in two experiments conducted on adult female New Zealand White rabbits. In Experiment 1, animals were trained in trace eyeblink conditioning followed by extinction, and memory retrieval was tested by presenting the CS at t…
Frontal sinus osteoma and palpebral abscess: Case report
2005
Osteomas of the paranasal sinuses are slow-growing, benign tumours most frequently found in the frontal sinus with an incidence that varies from 47% to 80% of the cases; there are often no symptoms and they are diagnosed by chance during an x-ray examination. The symptoms are usually headaches and those secondary to ocular or neurological complications. The therapy to be preferred is surgery. The authors describe a case of frontal osteoma complicated by frontal sinusitis and palpebral abscess.
Learning by heart : cardiac cycle reveals an effective time window for learning
2018
Cardiac cycle phase is known to modulate processing of simple sensory information. This effect of the heartbeat on brain function is likely exerted via baroreceptors, the neurons sensitive for changes in blood pressure. From baroreceptors, the signal is conveyed all the way to the forebrain and the medial prefrontal cortex. In the two experiments reported, we examined whether learning, as a more complex form of cognition, can be modulated by the cardiac cycle phase. Human participants ( experiment 1) and rabbits ( experiment 2) were trained in trace eyeblink conditioning while neural activity was recorded. The conditioned stimulus was presented contingently with either the systolic or dias…
Breathe out and learn: Expiration-contingent stimulus presentation facilitates associative learning in trace eyeblink conditioning.
2019
Rhythmic variation in heart rate and respiratory pattern are coupled in a way that optimizes the level of oxygen in the blood stream of the lungs and the body as well as saves energy in pulmonary gas exchange. It has been suggested that the cardiac cycle and respiratory pattern are coupled to neural oscillations of the brain. Yet, studies on how this rhythmic coupling is related to behavior are scarce. There is some evidence that, for example, the phase of respiration affects memory retrieval and the electrophysiological oscillatory state of the limbic system. It is also known that the phase of the cardiac cycle and hippocampal electrophysiological oscillations alone affect learning. Here, …
Laser treatment of giant xanthelasma palpebrarum
2013
Xanthelasma palpebrarum is the most common cutaneous xanthoma. It typically presents in middle-aged and older adults, most often around the eyelids. The diagnosis is made clinically. Giant xanthelasmas palpebrarum are xanthelasmas that extensively affect the superior and inferior bilateral eyelids. Many techniques have been put forward for treating these lesions (surgical, laser, and chemical techniques), but we describe our experience in the treatment of giant xanthelasmas by ultrapulsed CO2 laser. Between 2009 and 2012, in the Division of Plastic and Reconstructive Surgery at the University of Palermo, 12 patients with giant xanthelasmas were treated using a CO2 laser. The laser parameter…
Inside the Thompson laboratory during the “cerebellar years” and the continuing cerebellar story
2011
This paper is based on the talk by one of the authors (DL) given at the symposium for the retirement of RF Thompson (RF Thompson: A bridge between 20th and 21st century neuroscience). We first make some informal observations of the historical times and research conditions in the Thompson laboratory when the cerebellum was found to play a critical role in eye lid classical conditioning, the "cerebellar years". These conditions influenced our collaborative international program on the phenomenon known as "transfer of training" or "savings". Our research shows that the appearance of "savings" is an artifact of the order of testing, and depends upon the functioning of the contralateral interpos…
Interpositus nucleus inactivation reduces unconditioned response amplitude after paired but not explicitly unpaired treatment in rabbit eyeblink cond…
2001
The amplitude of unconditioned responses (URs) in unconditioned stimulus (US) alone presentations were measured in six rabbits during explicitly unpaired and classical conditioning treatments. After both phases of the experiment, the interpositus nucleus (IPN) was reversibly inactivated by a cold probe. URs after unpaired treatment were unaffected by inactivation but after acquisition of a robust level of conditioned responses (CRs), URs in US-alone test trials were reduced in amplitude compared with URs immediately before and after inactivation. The results suggest that the IPN has a role in CR-related reflex modification.
Cooling of the cerebellar interpositus nucleus abolishes somatosensory cortical learning-related activity in eyeblink conditioned rabbits.
2005
Nictitating membrane movement and multiple-unit activity in the somatosensory cortex were recorded from rabbits during paired (N = 6) and unpaired (N = 5) presentations of a tone conditioned stimulus (CS) and an airpuff unconditioned stimulus (US). A behavioural conditioned response (CR) to the CS and an accompanying neural response in the somatosensory cortex developed only in the paired group. Inactivation of the cerebellar interpositus nucleus abolished both the acquired CR and the accompanying neural response. However, the CS facilitated both behavioural and neural responses to the US during the inactivation. Thus, the absence of the CR could not be accounted for by the general inabilit…
Activity in the rabbit somatosensory cortex reflects the active procedural memory trace of a classically conditioned eyeblink response.
2003
Behavioral responses and neural responses in the somatosensory cortex were recorded in nine rabbits during the unpaired and paired treatments of classical eyeblink conditioning with a tone conditioned stimulus (CS) and an airpuff unconditioned stimulus. During the unpaired treatment, neither the behavioral nor neural responses to the CS were observed. During the paired treatment, behavioral conditioned response (CR), accompanied by neural activity, was developed. In well-trained animals occasional failures to elicit the CR were accompanied by an absence of neural responses. Nevertheless, the CS modified the behavioral unconditioned response in paired trials, implying that the CR-failures co…
Phase matters: responding to and learning about peripheral stimuli depends on hippocampal θ phase at stimulus onset.
2015
Hippocampal θ (3–12 Hz) oscillations are implicated in learning and memory, but their functional role remains unclear. We studied the effect of the phase of local θ oscillation on hippocampal responses to a neutral conditioned stimulus (CS) and subsequent learning of classical trace eyeblink conditioning in adult rabbits. High-amplitude, regular hippocampal θ-band responses (that predict good learning) were elicited by the CS when it was timed to commence at the fissure θ trough (Trough group). Regardless, learning in this group was not enhanced compared with a yoked control group, possibly due to a ceiling effect. However, when the CS was consistently presented to the peak of θ (Peak group…