Ipsilateral corticocortical connections of area PG of the brain in macaque monkeys

1990 ◽  
Vol 15 ◽  
pp. S77
Keyword(s):  
Macaque Monkeys ◽  
Corticocortical Connections ◽  
The Brain

Introduction

2021 ◽  
pp. 3-33
Author(s):  
Richard E. Passingham
Keyword(s):  
Human Brain ◽  
Brain Imaging ◽  
Spatial Resolution ◽  
Functional Brain Imaging ◽  
Functional Brain ◽  
Macaque Monkeys ◽  
Unique Pattern ◽  
The Brain ◽  
Inputs And Outputs

This chapter explains why this book is organized as it is. Each neocortical area has a unique pattern of inputs and outputs. This means that the challenge is to understand the transformation that each of the prefrontal (PF) areas performs from input to output. Functional brain imaging allows us to visualize the human brain at work, but it does not have the spatial resolution to identify the mechanisms that support the transformations that the brain performs. It is neurophysiological recordings from cells that tell us how these are achieved. Chapters 3–8 are therefore mainly devoted to studies that have been carried out on the PF cortex of macaque monkeys because the methods are necessarily invasive. Apart from recording, the methods include making selective lesions in an area; it is these that identify the contribution that is unique to that area. The book ends by reviewing the evolution of the human PF cortex; and the final two chapters discuss the ways in which the human PF cortex is specialized in terms of function. In doing so, they attempt to account for the intellectual gap between humans and other primates.

scholarly journals Access to the brain parenchyma using endovascular techniques and a micro-working channel

2017 ◽  
Vol 126 (2) ◽  
pp. 511-517 ◽  
Author(s):  
Johan Lundberg ◽  
Carina B. Johansson ◽  
Stefan Jonsson ◽  
Staffan Holmin
Keyword(s):  
Methylene Blue ◽  
Contrast Agent ◽  
Vessel Wall ◽  
Surgical Techniques ◽  
Brain Parenchyma ◽  
External Carotid ◽  
Macaque Monkeys ◽  
Angiography Suite ◽  
The Brain

OBJECTIVE Several older studies report a low risk for parenchymal access to the CNS by surgical techniques. In more recent studies, including those with post-puncture CT scans, there are indications that the risk of bleeding might approach 8%. New therapies, such as those that use viral vectors, modified mRNA, or cell transplantation, will probably warrant more parenchymal access to the CNS. Other minimally invasive routes might then be tempting to explore. This study was designed in 2 parts to address the possibility of using the endovascular route. The first aim was to test the ability to create a parenchymal micro-working channel to the CNS in macaque monkeys through the vessel wall. Second, the biocompatibility of a device-associated, detached, distal securing plug that was made of nitinol was investigated in swine for 1 year. METHODS Trans-vessel wall intervention in the middle cerebral artery and associated cerebral parenchyma was performed in 4 rhesus macaque monkeys using a full clinical angiography suite. A contrast agent and methylene blue were injected to test the working channel and then detached at the distal end to act as a securing plug through the vessel wall. One-year follow-ups were also performed using angiography and histological analysis in 10 swine with 24 implants that were distributed in the external carotid artery tree. RESULTS The cerebral interventions were performed without acute bleeding. Both the contrast agent and methylene blue were infused into the brain parenchyma and subarachnoidal space via the endovascular micro-working channel (7 injections in 4 animals). In the 1-year follow-up period, the implant that was left in the external carotid vessel wall in the swine was covered by the endothelium, which was followed by dislodgement just outside the blood vessel with thin capsule formation. No stenosis in the artery was detected on 1-year angiography. The animals showed normal behavior and blood sample results during the follow-up period. This is the first histological demonstration of nitinol biocompatibility when the implant is positioned through an arterial wall and indicates that the trans-vessel wall technique is not comparable with stent placement and its ability to induce intimal hyperplasia and restenosis. CONCLUSIONS This study demonstrates that the trans-vessel wall technique is applicable to brain intervention in macaque monkeys, providing a micro-working channel for delivery or sampling. The long-term follow-up study of the detached device in swine showed no clinical or biochemical complications and a normal angiography appearance.

scholarly journals Bottom-up but not Top-down Attention Dominates the Value Representation in the Orbitofrontal Cortex

2021 ◽  
Author(s):  
Wenyi Zhang ◽  
Yang Xie ◽  
Tianming Yang
Keyword(s):  
Cognitive Processes ◽  
Orbitofrontal Cortex ◽  
Early Stage ◽  
Top Down ◽  
Luminance Change ◽  
Bottom Up ◽  
Macaque Monkeys ◽  
Functional Roles ◽  
Stimulus Salience ◽  
The Brain

The orbitofrontal cortex (OFC) is essential for value-based learning and decision making. Understanding the attentional modulation of the representation of value in the OFC provides us key information on its functional roles and links the OFC to other cognitive processes. We examined how top-down and bottom-up attention modulates the value encoding in the OFC. Two macaque monkeys were trained to detect a luminance change at a cued location between a pair of visual stimuli, which were over-trained pictures associated with different amount of juice rewards and, thus, different salience. While the monkeys' behavior and the DLPFC neuronal activities indicated that the monkeys actively directed their attention toward the cued location during the task, the OFC neurons' value encoding, however, was dominated by the bottom-up attention based on stimulus salience and only reflected the top-down attention weakly. The disassociation between the top-down and bottom-up attention signals in the OFC indicates that the OFC occupies an early stage of value information processing in the brain.

scholarly journals Macaque monkeys learn and perform a non-match-to-goal task using an automated home cage training procedure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stefano Sacchetti ◽  
Francesco Ceccarelli ◽  
Lorenzo Ferrucci ◽  
Danilo Benozzo ◽  
Emiliano Brunamonti ◽  
...  
Keyword(s):  
High Performance ◽  
Home Cage ◽  
Training Procedure ◽  
Macaque Monkeys ◽  
Challenging Tasks ◽  
Electrophysiological Studies ◽  
Stable Performance ◽  
The Brain ◽  
High Performance Level ◽  
Made In

AbstractIn neurophysiology, nonhuman primates represent an important model for studying the brain. Typically, monkeys are moved from their home cage to an experimental room daily, where they sit in a primate chair and interact with electronic devices. Refining this procedure would make the researchers’ work easier and improve the animals’ welfare. To address this issue, we used home-cage training to train two macaque monkeys in a non-match-to-goal task, where each trial required a switch from the choice made in the previous trial to obtain a reward. The monkeys were tested in two versions of the task, one in which they acted as the agent in every trial and one in which some trials were completed by a “ghost agent”. We evaluated their involvement in terms of their performance and their interaction with the apparatus. Both monkeys were able to maintain a constant involvement in the task with good, stable performance within sessions in both versions of the task. Our study confirms the feasibility of home-cage training and demonstrates that even with challenging tasks, monkeys can complete a large number of trials at a high performance level, which is a prerequisite for electrophysiological studies of monkey behavior.

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