<p><strong>Short answer</strong><br>
The function of the thalamic adhesion in humans is unknown.</p>

<p><strong>Background</strong><br>
The two halves of the thalamus are separated by the third ventricle. In about 80% of people, the thalami are connected via the <a href="https://en.wikipedia.org/wiki/Interthalamic_adhesion" rel="nofollow noreferrer">thalamic adhesion</a> (<em>massa intermedia</em>, Fig. 1), which mainly contains cell bodies, but also commissural fiber systems that connect some thalamic nuclei (<a href="http://www.ijav.org/2010/ijav_10_174-175.pdf" rel="nofollow noreferrer">Satheesha &amp; Soumya, 2010</a>; <a href="http://www.ijav.org/2010/ijav_10_174-175.pdf" rel="nofollow noreferrer">Sen <em>et al</em>., 2005</a>). Because the structure is absent in about 20% of the people, it is not a critical structure. The significance and consequences of its presence or absence is not known in humans (<a href="http://www.ijav.org/2010/ijav_10_174-175.pdf" rel="nofollow noreferrer">Sen <em>et al</em>., 2005</a>). </p>

<p>It is known that there are sex-differences between the presence of the structure. It is present in 78% of females and 68% males <a href="http://www.ncbi.nlm.nih.gov/pubmed/1744245" rel="nofollow noreferrer">(Allen &amp; Gorski, 1991)</a> and it is about 50% bigger in females, when present. In schizophrenics, female patients were shown to have a significantly higher incidence of absent <em>massa intermedia</em> (33%) than their healthy controls (14%), whereas male patients showed no such difference <a href="http://linkinghub.elsevier.com/retrieve/pii/S0920996400000670" rel="nofollow noreferrer">(Nopoulus <em>et al</em>., 2001)</a>.    </p>

<p>In rhesus monkeys, ablation of the structure has been shown to lead to ipsilateral motor deficits <a href="http://brain.oxfordjournals.org/content/95/2/347" rel="nofollow noreferrer">(Lumley, 1972)</a>, but that has likely no relation to the commmissural tracts in question.  </p>

<p><a href="https://i.sstatic.net/5q5v9.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/5q5v9.png" alt="CI"></a><br>
<sup>Fig. 1. Dissection showing the <em>massa Intermedia</em> connecting the two thalami through the third ventricle. source: <a href="https://en.wikipedia.org/wiki/Interthalamic_adhesion" rel="nofollow noreferrer">Wikipedia</a></sup></p>

<p><sub><strong>References</strong><br>
<strong>-</strong> <a href="http://www.ncbi.nlm.nih.gov/pubmed/1744245" rel="nofollow noreferrer">Allen &amp; Gorski, <em>J Comp Neurol</em> (1991); <strong>312</strong>(1):97-104</a><br>
<strong>-</strong> <a href="http://brain.oxfordjournals.org/content/95/2/347" rel="nofollow noreferrer">Lumley, <em>Brain</em> (1972); <strong>95</strong>(2): 347-56</a><br>
<strong>-</strong> <a href="http://linkinghub.elsevier.com/retrieve/pii/S0920996400000670" rel="nofollow noreferrer">Nopoulus <em>et al</em>., <em>Schizophr Res</em> (2001); <strong>48</strong>(2-3): 177-85</a><br>
<strong>-</strong> <a href="http://www.ijav.org/2010/ijav_10_174-175.pdf" rel="nofollow noreferrer">Satheesha &amp; Soumya, <em>Int J Anatomic Va</em>r (2010); <strong>3</strong>: 174–5</a><br>
<strong>-</strong> <a href="http://www.ijav.org/2010/ijav_10_174-175.pdf" rel="nofollow noreferrer">Sen <em>et al</em>., <em>Neuroanatomy</em> (2005); eISSN 1303-1775 • pISSN 1303-1783</a></sub> </p>

CC BY-SA 3.0
2016-05-19T20:20:32.497Z
2016-05-19T20:25:41.177Z
2016-05-19T20:25:41.177Z
AliceD
<p>What kind of direct exchange do we have between the two halves of the thalamus, whether going through the thalamic adhesion or not? Do we know what parts of left and right thalamus are connected and what kind of information they exchange? </p>

<neuroscience><neuroanatomy><neurophysiology>
What is the function of the connection between the two halves of the thalamus?
ceillac
# What is the function of the connection between the two halves of the thalamus?

(Asked by: username_0 on 2016-05-15)

What kind of direct exchange do we have between the two halves of the thalamus, whether going through the thalamic adhesion or not? Do we know what parts of left and right thalamus are connected and what kind of information they exchange?

**Tags:** neuroscience, neuroanatomy, neurophysiology


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## 1 answers

### Answer by username_1 on 2016-05-19. Score: 2

**Short answer**  
The function of the thalamic adhesion in humans is unknown.

**Background**  
The two halves of the thalamus are separated by the third ventricle. In about 80% of people, the thalami are connected via the [thalamic adhesion](https://en.wikipedia.org/wiki/Interthalamic_adhesion) (*massa intermedia*, Fig. 1), which mainly contains cell bodies, but also commissural fiber systems that connect some thalamic nuclei ([Satheesha & Soumya, 2010](http://www.ijav.org/2010/ijav_10_174-175.pdf); [Sen *et al*., 2005](http://www.ijav.org/2010/ijav_10_174-175.pdf)). Because the structure is absent in about 20% of the people, it is not a critical structure. The significance and consequences of its presence or absence is not known in humans ([Sen *et al*., 2005](http://www.ijav.org/2010/ijav_10_174-175.pdf)).

It is known that there are sex-differences between the presence of the structure. It is present in 78% of females and 68% males [(Allen & Gorski, 1991)](http://www.ncbi.nlm.nih.gov/pubmed/1744245) and it is about 50% bigger in females, when present. In schizophrenics, female patients were shown to have a significantly higher incidence of absent *massa intermedia* (33%) than their healthy controls (14%), whereas male patients showed no such difference [(Nopoulus *et al*., 2001)](http://linkinghub.elsevier.com/retrieve/pii/S0920996400000670).

In rhesus monkeys, ablation of the structure has been shown to lead to ipsilateral motor deficits [(Lumley, 1972)](http://brain.oxfordjournals.org/content/95/2/347), but that has likely no relation to the commmissural tracts in question.

[![CI](https://i.sstatic.net/5q5v9.png)](https://i.sstatic.net/5q5v9.png)  
Fig. 1. Dissection showing the *massa Intermedia* connecting the two thalami through the third ventricle. source: [Wikipedia](https://en.wikipedia.org/wiki/Interthalamic_adhesion)

**References**  
**-** [Allen & Gorski, *J Comp Neurol* (1991); **312**(1):97-104](http://www.ncbi.nlm.nih.gov/pubmed/1744245)  
**-** [Lumley, *Brain* (1972); **95**(2): 347-56](http://brain.oxfordjournals.org/content/95/2/347)  
**-** [Nopoulus *et al*., *Schizophr Res* (2001); **48**(2-3): 177-85](http://linkinghub.elsevier.com/retrieve/pii/S0920996400000670)  
**-** [Satheesha & Soumya, *Int J Anatomic Va*r (2010); **3**: 174–5](http://www.ijav.org/2010/ijav_10_174-175.pdf)  
**-** [Sen *et al*., *Neuroanatomy* (2005); eISSN 1303-1775 • pISSN 1303-1783](http://www.ijav.org/2010/ijav_10_174-175.pdf)


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