Taste and smell compared:
taste and smell (olfaction) are
chemical senses in opposition to
the other three special senses.
Between themselves however, they
show features of a 0-00 polarization.
A simple observation is the locations
in one versus two openings respectively,
taste ventrally, smell more distally;
left and right nerve bulbs in the
nostrils operate also separately.
Taste receptors on tongue
is an unpaired* sense, while smell
becomes a paired sense already in
there exist species that have taste
senses on the legs!)
concerns directly the nutrition
system, originating from the vegetative
0-pole, and is a "near sense",
while smell concerns the environment,
is a "long-distance sense"
(which also gets involved in communication
as a language): a polarity of the
type center - circumference.
Smell receptors are nerve cells
with own axons. It is the only sense
with receptors that are neurons
with direct connections with cortex
in the brain. Whole cerebrum has
been interpreted as developed from
the olfactory cortex. Thus, smell
has the closest relation to the
neural system, the 00-pole of the
The sense of taste
differentiates only among up to
6 (?) different tastes, the sense
of smell of some animals up to 10-20
millions: a polarity between unity
There is also
a difference between levels of complexity
in registered chemicals: small atomic
ions and atomic groups decides tastes,
more complex molecules are registered
by the sense of smell.
of stimuli occurs for the simplest
tastes salty and sour through chemically
gated ion channels, for the little
more complex other tastes through
G-proteins and secondary messenger,
cAMP-gated channels, as does the
transduction in the olfactory sense.
A partial polarity.
of microvilli of taste receptors
is vertical to upper surface of
tongue. The corresponding dendrites
of smell neurons are "horizontally"
spread at right angle to the cells
along the surface of the mucous
membrane: a geometrical angle step
and polarity of d-degree 3 in our
model that derives from the 0-00-polarity.
Finally, opposite directions
in breathing (cf. directions from
00- and 0-poles) is connected with
smell versus taste: It is during
exhalation that the smell sense
contributes to the "flavor"
- in contrast to that of
proper smell which occurs during
the inhalation phase (Wikipedia).
2. Taste (gustation):
3 appears both in types of papillae
and in number of nerves (Nf p.
421) from tongue via bipolar
cells to spinal cord. Of the 3 papillae
types 2 have taste buds, 1 only
a function of friction.
- Fungiform type of papillae
has about 5 taste buds.
type is bigger and has up to
about 100 buds (Aph).
The bigger circumvallate type
is mostly gathered in a v-form on
back of the tongue, while it seems
as if the fungiform type of papillae
are more lengthwise arranged. If
so, they represent a certain angle
bud in a pore consists of receptor
cells with specialized epithelium
and is a collection of ca. 40 cells
shaped as thick leaves as in an
Already these features
- and the innervation by 3 different
cranial nerves - show the general
principle of polarizations:
- Front 2/3
of tongue is innervated by branches
of the fascial nerve VII,
part of tongue by the glossopharyngeal
nerve IX and by branches from the
vagus nerve X,
- taste buds
furthest back in pharynx and epiglottis
by this vagus nerve X.
there are steps in depth between
branches of these cranial nerves,
which also serve other parts in
similar steps from surface to depth
in the body:
the face, IX the head and neck,
X the inner visceral organs. Something
to remember when it comes to the
"5" tastes - or 5 + 1:
Simplifying incomplete data, the
5 hitherto identified tastes (besides
water) could be arranged in three
groups of increasing complexity:
from simple atomic ions to small
(end)-groups of OH (as in carbohydrates)
and NHx in nitrogen substances to
these both groups appearing in amino
acids and small peptides:
the arrows below.
Sweet and bitter, it's said, show
a certain feature of complementarity
reminding of complementary colors:
many sweet substances are followed
by a bitter taste, especially if
the stimulus moves from apex of
tongue inwards its base (Nf p.
- Umami is (especially?)
identified at the bigger circumvallate
papillae in v-form back on the tongue
looks somewhat like polarization
steps from umami to the N-O-polarity
in bitter-sweet to the simple ions
and salty character of a first environment.
So too with regard to valences of
- in umami C-N-O
= valences 4-3-2, in bitter - sweet
N-O = 3-2,
- in sour H+ 1,
in NaCl 0 (+/-1);
also a way from living cells as
centers in an environment as anticenter.
Water, a taste detected in humans
and some other animals, seems to
be registered especially by taste
buds in pharynx, furthest back.
umami as a first fundamental polarization
? ) Thus, it should be innervated
by the vagus nerve which mainly
goes to inner, visceral organs:
an eventual connection with thirst?
Could thirst and hunger be connected
in a common center in hypothalamus?
About localization, old maps
are shown to be false. All the 4
best known tastes are detected by
all taste buds. There is however
certain indications that sensitivity
for salty and sweet tastes are higher
on front part of the tongue, sensitivity
for sour and bitter higher further
back (Aph p. 553). It could
hypothetically imply a factor of
direction (d-degree 4) appearing
here, a polarization outward /
inwards within the groups as shown
with the vertical arrows in the
figure above. (Cf. about complementary
sensations sweet-bitter above (Nf).
Sensitivity for the "inward
directed" tastes is much higher
than the other: for sour taste it's
1000 times stronger than for sweet
and salty, for bitter taste still
100 times stronger (Aph). Hence,
there would be values 1 - 3 - 5
on the log-scale between these tastes.
the sense of taste seems very simple
compared with sense of smell: the
sensory bipolar cells mediate the
signals directly from receptor cells
to spinal cord and medulla oblongata.
There are no other cell layers out
at the organ.
there is a polarization between
very thin and thicker nerve endings
at the membranes of receptor cells.
Further, one nerve branches to many
receptor cells and each of these
receives ends from many nerve branches:
a system of divergence and convergence.
(Unsaid if this arrangement gives
blended tastes and has a function
of discrimination or something else.)
It's said that the taste buds
include 4 different types of cells.
Stem cells are mentioned, curiously
also innervated, as the matured
receptors. (It's unknown if they
take part in sensations.)
is no adaptation in receptors, only
in higher centers.
of taste buds is said to be about
10.000 in newborn human babies and
medium about 3000 in adults.
3. Smell - olfaction:
are able to distinguish between
ca. 2000 - 4000 odorants (animals
like dogs as well-known an awful
has been studies identifying at
least 50 primary smells; if so an
interesting number, one 10-power
more than the number of tastes.
that the olfactory receptors are
the only ones with own axons to
the brain, and that the olfactory
brain is seen as origin for the
whole cerebral cortex seems to indicate
that this sense made up the very
front of the neural tube in earlier
brains; closest to the surrounding
anticenter as polarizing force in
our model. (Cf. that insects have
the same organs on antennae.) This
could be a reason for the multitude
of differentiations and genes coding
for proteins in the olfactory system?
(reference here Wikipedia.):
From the parts of mucous
membrane that are covered with sensory
neurons, the axons penetrate the
bone into a bulb just inside.
bulbs an outer layer of axons from
many neurons gather intertwined
in what is called glomeruli, as
it seems a unique kind of convergence,
not associated with synapses on
dendrites of cells, yet gathered
in small round bladders. If so,
perhaps an early form of centered
network during evolution, an intermediate
form between the simpler nerve branching
at taste receptors and later bipolar
cells replacing them?
mitral cells in a deeper layer of
the bulb gathers stimuli from many
glomeruli (like ganglion cells in
vision) - and from mitral cells
the axons gather to the olfactory
tract, entering the brain.
the mitral cells there are two other
types in the bulbs, periglomerular
cells and granular cells
for lateral inhibition. Cf. two
corresponding layers in vision.)
It makes 4 type
of cells out at the organ (the stem
cells not included), to compare
with 5 in vision.
taste receptors these chemical receptors
are renewable - perhaps depending
on the higher dimension degree (shortened
d-degree) of chemical senses
compared with those for EM-waves
and mechanical stimuli according
to our interpretations (end of file
as in the taste organ at synapses
in higher centers, not at receptive
convergence is of the same degree
as between bipolar cells and rods
a factor of ca. 1000: 25000 axons
synapsing on ca. 25 mitral cells.
(Once again factor 5!?)
the figure below an effort to interpret
the information. Here the number
of different distinct features of
molecules is reduced to 5, a-b-c-d-e.
They are naturally many more - and
probably of both structural (geometrical),
chemical and electric kinds (?).
levels in language are marked in
the figure. (The cortical neurons
may remind of gathered Egyptian
hieroglyphics within frames as "speech
bubbles" referring to Pharaohs.)
Odors as pheromones and others have
also the function of a language
between individuals of a specie
and are actively produced by scent-glands.
structural analysis of an odor seems
to go stepwise from brain to receptor
neurons. (Synthesis the other, afferent
1. Each receptor recognizes
only a particular molecular feature
or class of odor molecules. There
are receptor populations with distinct
glomerulus gathers nerves from these
populations that detect similar
features in a molecule.
Different glomeruli register different
features of one and the same molecule.
Each mitral cell gathers signals
from many glomeruli.
bulb many neurons (must refer to
the mitral cells) are responsive
to many different odors.
cortex of the brain however, half
neurons respond only to one odor,
the rest to only a few. Scientists
have different theories and imagine
a kind of "spatial" or
"chemotopic map" in cortex
for each odor.
far Wikipedia, Olfaction.)
there are no intermediate cells
for convergence, it should mean
that the afferent axons from mitral
cells diverge to different neurons
in cortex and that a neuron in cortex
only responds to the right combination
of signals from mitral cells as
supposed in the figure above.
- memory - feelings:
smell sensations have connections
with long-term memory as well as
with elementary feelings is well-known.
from smell organs distribute signals
to 5 different areas in the brain.
3 pathways go to cortex, the limbic
system around the 3rd ventricle
and to hypothalamus with its neurosecretion.
Hippocampus and Amygdala, associated
with the limbic system, are locations
for long-term memory and elementary
feelings. One example is fright
and fishes that flee from the smell
of dead fish.
It has been
found that there are single neurons
in cortex that answer distinctly
on e. g. photos of a certain known
person and on nobody else, as if
the whole memory of that person
with all its features was stored
in one cell.
conclusion seems to be that Memory
as such is organized in a similar,
intricate way as Olfaction, gathering
structural pieces from a lot of
senses. (Analysis of grammar in
language in a similar way?)
between the sense of smell (chemical)
and of vision (electromagnetic)
are noted in Wikipedia. It concerns
the way of analysis in distinct
features, the system of lateral
inhibition out at the organ and
especially the unique fact that
ion channels in receptor cells are
directly opened by cAMP and cGMP
respectively, without mediating
enzyme (protein kinase A). It's
suggested that there eventually
have been an evolutionary development
from one of the senses to the other.
The fact about
opening of ion channels is perhaps
an example of protein enzymes as
a later phase during evolution with
more and more of intermediators?
(Cf. human societies.). The same
could be the case in the difference
between these senses: glomeruli
in olfaction versus bipolar cells
developed in vision?