Cyclopia: The Face Predicts the Future.

The most extreme form of holoprosencephaly (HPE) is cyclopia and appears with a single characteristic midline diamond-shaped orbital structure and various facial, brain, and extrafacial features. We aimed to report a case of a cyclopic fetus diagnosed at the 22 weeks of the gestational age and further we reviewed the recent literature in order to highlight the etiopathogenesis and set goals for approaching such future pregnancies. Following the first-trimester assessment, in a 27-year-old pregnant woman, who underwent in vitro fertilization, the pregnancy was associated with a low risk for aneuploidies and a high risk for pre-eclampsia.

Response properties of saccade-related neurons of the post-arcuate premotor cortex.

We studied the phasic saccade-related discharges of single neurons (S neurons) of the premotor cortex of female rhesus monkeys, mostly in the caudal bank of the arcuate sulcus. As described in previous work from our laboratory (Neromyliotis E, Moschovakis AK. Front Behav Neurosci 11: 1-21, 2017), some of these cells emitted phasic discharges for coordinated movements of the eyes and hand as well as for movements of either effector executed in isolation (motor equivalence, Meq).

Saccades evoked in response to electrical stimulation of the posterior bank of the arcuate sulcus.

To test the hypothesis that the premotor cortex in and behind the caudal bank of the arcuate sulcus can generate saccades, we stimulated electrically the periarcuate region of alert rhesus monkeys. We were able to produce saccades from sites of the premotor cortex that were contiguous with the frontal eye fields and extended up to 2 mm behind the smooth pursuit area. However, premotor sites often elicited saccades with ipsiversive characteristic vectors, lower peak velocities, and flatter velocity profiles when compared to saccades evoked from the frontal eye field.

Response Properties of Motor Equivalence Neurons of the Primate Premotor Cortex.

To study the response properties of cells that could participate in eye-hand coordination we trained two macaque monkeys to perform center-out saccades and pointing movements with their right or left forelimb toward visual targets presented on a video display. We analyzed the phasic movement related discharges of neurons of the periarcuate cortex that fire before and during saccades and movements of the hand whether accompanied by movements of the other effector or not. Because such cells could encode an abstract form of the desired displacement vector without regard to the effector that would execute the movement we refer to such cells as motor equivalence neurons (Meq).

Topography of Visuomotor Parameters in the Frontal and Premotor Eye Fields.

To determine whether the periarcuate frontal cortex spatially encodes visual and oculomotor parameters, we trained monkeys to repeatedly execute saccades of the same amplitude and direction toward visual targets and we obtained quantitative images of the distribution of metabolic activity in 2D flattened reconstructions of the arcuate sulcus (As) and prearcuate convexity. We found two topographic maps of contraversive saccades to visual targets, separated by a region representing the vertical meridian: the first region straddled the fundus of the As and occupied areas 44 and 6-ventral, whereas the second one occupied areas 8A and 45 in the anterior bank of the As and the prearcuate convexity. The representation of the vertical meridian runs along the posterior borders of areas 8A and 45 (deep in the As).