"Like the muscle spindle system, the Golgi tendon organ system is not a
closed loop. The Ib inhibitory interneurons also receive synaptic inputs from
a variety of other sources, including cutaneous receptors, joint receptors,
muscle spindles, and descending upper motor neuron pathways (Figure 16.12).
Acting in concert, these inputs regulate the responsiveness of Ib
interneurons to activity arising in Golgi tendon organs."
Is the author using "closed loop" in a non-typical way in the above
paragraph? Earlier on the same page the circuit is referred to as "negative
feedback system" so surely, the loop must be closed? A closed loop can still
receive reference signals from other circuits?
"Like the muscle spindle system, the Golgi tendon organ system is not a
closed loop. The Ib inhibitory interneurons also receive synaptic inputs from
a variety of other sources, including cutaneous receptors, joint receptors,
muscle spindles, and descending upper motor neuron pathways (Figure 16.12).
Acting in concert, these inputs regulate the responsiveness of Ib
interneurons to activity arising in Golgi tendon organs."
Is the author using “closed loop” in a non-typical way in the above
paragraph? Earlier on the same page the circuit is referred to as "negative
feedback system" so surely, the loop must be closed? A closed loop can still
receive reference signals from other circuits?
RM: Got me? There seems to be an allergic reaction to control theory in neuroscience. I think it has to do with not noticing (or not wanting to notice) that these loops can be closed through the outside world.
"Like the muscle spindle system, the Golgi tendon organ system is not a
closed loop. The Ib inhibitory interneurons also receive synaptic inputs from
a variety of other sources, including cutaneous receptors, joint receptors,
muscle spindles, and descending upper motor neuron pathways (Figure 16.12).
Acting in concert, these inputs regulate the responsiveness of Ib
interneurons to activity arising in Golgi tendon organs."
Is the author using "closed loop" in a non-typical way in the above
paragraph? Earlier on the same page the circuit is referred to as "negative
feedback system" so surely, the loop must be closed? A closed loop can still
receive reference signals from other circuits?
Just from the bit you quote and your comment, I would guess that they are using "open" and "closed" here in the sense of "open system" (susceptible to outside influences) as against "closed system" (shielded from outside influences). The "loop" is the system and "open" and "closed" are not intended to refer to whether the loop is broken.